A lot of Honda players complain about Honda being shit, but he's probably mid-tier IMO (middle of the road). SFIV is a different game than II, much like III is a different game from either of these. Don't go in thinking it's a replica of SFII and you should be fine.

As for online, be prepared to fight Ken, Ryu and Akuma over and over again.
 
However seeing as you got it on PC (steam?), I would be willing to add you and play you sometime :D

Awesome, another PC player. Add me up (Gamertag is the same as my username) 
  
As for coming from II to IV, I did the same and, well, I was able to get a grasp of it all quicker than most, I'd say. It'll be a shock when you first jump online, but at least you'll have a better concept of basic strategies with some of the characters.

If you know what to do with Honda, he is a great character.  Sure he does have his issues (tough getting through fire ball spammers, tough time against turtles), but he does massive damage.  I'm a Honda player myself and I love the fat bastard.  My gamer tag is JJOR64.  I own the PC version as well so we can play some time.

My best advice is to learn the basics.  I "played" SFII when I was younger, but I wasn't good at it and there was no type of scene to speak of.  I learned by doing a couple of things: 

Go into challenge mode and try out all the characters.  If you like Honda, stick with him.  Learn his combos and how to apply them.
 
Watch videos on YouTube.  This is an invaluable tool.  I learned so much just by watching.
 
Go to Shoryuken.com and read up on Honda.  Very good info there. 

I've messed around with all major Charge chacters (except Chun-li and Guile) and I must say E.Hondas game is very basic so good for beginners but it defiantly is up there in terms of over all depth
 
Basically learn the tick in command throw. and how to anti air with headbutt/ultra and ur good. If you really take some risks pianoing cr.lp xx hp hands --> cr.lp xxx hp hands xx super would be the ultimate goal. Although JJOR cant even do that (at lest I've never seen him do it) so its not 100% game breaking.

Vodun Valkyrie is my gamertag, see you in there

Another person to welcome to SFIV, hooray :D
 
Just spam his light buttdrop move over and over and you'll do fine!

"Although JJOR cant even do that (at lest I've never seen him do it) so its not 100% game breaking. "

I've been maining Honda for awhile and I can give you some info. He's not a bad character, like ultima said he's about midtier. He has generally even matchups but a few really bad matchups. The reason he's worse in sfiv than other sf games is all his specials are slower and more obvious, and his hundred hand slap range is greatly decreased and harder to get out as part of a combo. 
 
If you're going to play on a fightpad (by fightpad I assume you're talking about the regular shaped controller with 6 facebuttons) then I dont recommend using charge characters or characters who require fast mashing to get a special move out. Honda falls under both of these categories and should really only be played on a fight stick. There are some combos you can learn without the stick but you won't be able to do his hundred slap move as part of a combo unless you do something crazy like map one button to light punch and the rest to hard punch lol.
 
If you decided to get an arcade stick or if you want to be dumb and play honda on a pad then I'll be more than willing to give you some pointers.

He is the one of the characters i always loose too . Its that damn headbutt thing he does . It destroys balrog .

" @turbomonkey138: Actually the Balrog Honda match is in Balrogs favour. "

Gandalf > Balrog 
Toyota > Honda

" Gandalf > Balrog 
Toyota > Honda "

" Gandalf > Balrog Toyota > Honda "

" @turbomonkey138: you can punish mp and hp headbutt with lp dash punch. IF timed correctly a crouching hp will beat honda's buttslam. Also if you sit there jabbing you will beat all of honda's headbutts even ultra lol "