The concept of a practice league seems enticing for new players such as myself to get the hang of the intimidating starcraft multiplayer.  It has allowed me to not get completely steamrolled and win 2 out of 3 because I'm playing complete noobs like me.  I think the practice league is great so far but looking around of forums there has been many warnings from players saying that not only will playing in this league not benefit you but it will be a detriment to your progression because of the slower game speed. 
 
Am I doing myself a disservice by playing in the practice league?  What is your perception of the league?

It's good for the basics, try some matches against the ai if you want to try some full speed games.

Personally I'm too frightened of multi-player to even try the practice matches, so kudos to you for giving it a shot! Obviously because of my cowardice I'm not a great authority but I can't really see how playing in the practise league can *hurt* your game. Unless playing 20 (is it 20?) matches at a slower speed against unranked opposition is enough to take the edge off the razor sharp skills you wouldn't have as a beginner player...  
 
Or maybe if you do your placement matches with 0 or very little experience, you'll be placed in a lower tier than you would be if you had played some practise matches? So you'll be higher in a lower bracket vs lower in a higher bracket? I have no idea. I would say though that the challenge levels have definitely helped my confidence (apparently not enough, but still) so if you haven't tried those out yet you should take a look!

The idea that it hurts your play is likely aimed at competitive players, since playing there would cause you to develop skills that could hurt you in the long run, but if you're just playing for fun, I say go for it. You're not going to have any fun getting steam-rolled at full-speed, so why not get a hang for build-orders and such in the practice league first?

Kinda, if you are a total noob where you don't even know how to scout or mass or expand or anything, then those 50 practice games will give you games where you can learn that stuff. Yes the big rocks there and the slower game speed theoretically harms you, but if you get more cons out of it than pros of learning the game in practice league; then perhaps you aren't as much of a noob as you thought. 

Yah, the lack of challenge made me skip it.  I got dropped to bronze last night some reason and now I'm steamrolling my way back to silver.

I agree with the posts that you've read. The novice maps that protects from rush and the lower game speed will make you much worse when you enter the real deal.
 
You need to know how to scout and counter a zerg rush for example, and you need to get used to the fast pace of the game. I'd recommend practicing against the AI in custom games and checking out youtube channels like HDstarcraft that shows commentated replays of some of the best starcraft players, this will show you some basic strategies. Also read about strategies and things like build orders on the forums.
The challenges that you can do under 'single player' are also an okay way to learn unit counters.
 
Also I would choose one race you like, to begin with and focus on that one, with things like what to do against each specific faction in different situations. But at the same time you need to know every unit and building in the game too, so don't neglect everything besides one race.
 
I'd say the most important thing is knowing what you can do in a given situation. When you've played and read enough, you know what to do, and you probably have a standard build order that you alter based on the opponent and what you scout. For example if you scout a dark shrine in a protoss base you need to build a unit that can detect invisibility, otherwise his dark templars will destroy you. Or if you scout a zerg base quickly and he still has only 5  - 7 drones and a spawning pool is coming up, he is probably rushing you with zerglings. 
 
EDIT: Also, even though it is of course a personal opinion, you really don't need to be an expert to simply win a match. That is exactly what the lower ladders are for. I played a fair amount in the beta where I got the hang of it, and after release I have played with a Guest/Friend code trial of the game, and positioned in Platinum and did quite well there. Just go with it and watch your replays, and learn from your mistakes and you will be winning matches soon enough.

The practice league definitely isn't cool, it allows for strategies that are unbeatable, since you can't scout.
 
Lifting off to the gold, warping in outside of rocks, Terran putting unit producing structures outside of rocks, and zerg just macroing up (like 20 drones before pool and such) are all ridiculous tactics that can't be stopped due to the novice maps.

It's good for getting to grips with the bare minimum of the game, and just getting a feel for it, but I wouldn't play 50 matches there if I was new, the whole idea of not allowing to rush and harrass, paired with the slow game speed, simply isn't how starcraft 2 should be played.