The Classical Drawing Atelier may be a bit rough for a beginner, but I would still suggest eventually picking up, additional things that can help you GREATLY:
http://www.itchstudios.com/psg/art_tut.htm - Read this first
http://www.scribd.com/doc/24522437/Norling-Perspective-Made-Easy - This is for perspective, you definitely must learn
http://emptyeasel.com/2006/11/24/9-steps-to-creating-better-compositions/
http://emptyeasel.com/2008/11/18/avoiding-tangents-9-visual-blunders-every-artist-should-watch-out-for/
http://emptyeasel.com/2009/11/17/how-to-draw-a-portrait-of-the-head/ - Just a good tutorial on how to structure a head, you can easily apply this to other parts of the body, the whole figure, anything really!
http://processjunkie.blogspot.com/2007/09/best-figure-drawing-books-ever.html - You definitely want the Loomis and Bridgman books.

Theres tons more books out there but those should keep you busy. Look, basically at this point you have two options, you can either start dedicating some time to fundamentals, take a break from pixel art, or you can decide not to, either stop doing art altogether or keep posting here, but if we can't help you improve people are probably going to stop posting in your threads, to be honest if you chose this I probably wouldn't and any new people that would want to help would be turned off because they wouldn't see any improvement and even if they gave you the most helpful critiques in the world you wouldn't be able to wrap your head around them, so you'd just end up wasting your and everyone else's time. Once again I'm really not trying to be mean, I know I am pretty blunt but I'm just trying to tell you what would end up happening, i want you to improve, we all do, or else we wouldn't be taking this much time to do so. But as a lot of us have stated before, we can't help you unless you know what we're talking about.

Bieber Boy... who exactly are you? You came onto the board and instantly defended xhunterko, I suspect you could actually be him (I'm probably wrong, maybe a friend then?)... and the comment you just made was fairly rude, he was only trying to help, it seems like you're trying to entice a fight. I suggest you cut it out man or the mods will be on you, they're pretty strict on their rules and they don't want people getting into flame wars.

Oh jeez you're bumping this? I've kinda moved on... hurm, as always I will always take critique into consideration but I'll have to think if I still want to continue this sprite or not. (If you don't see me edit this with an updatee you'll know)

Xiphirx I'm not exactly sure how thats supposed to uhh, help him out. If you were inspired by it or something maybe it'd be in your best interest to make a new topic on it so people can critique it on there.

You didn't address the issue with the clouds at all, look you're still struggling with fundamentals in art, after months, I don't know how but you really have to get a grip on it. To be blunt, the sky doesn't work that way, clouds don't work that way, trees don't work that way, grass doesn't work that way. You need to start looking at images for reference, you should probably be drawing lots of still life and you should probably pick up some beginner art books.

I mean unless you don't care to improve at all, which is fine, you can do what you want, but I haven't seen any improvement from you at all ever since you started posting here, perhaps barely, if you want to be successful you should put the pixels down and start working on improving your artistic ability. I feel like a broken record at this point though, I've said this at least twice and I'm sure others have said similar things to you, this is after-all a critique board, a fairly serious one at that, how can we help you if you don't really get what we're trying to tell you(not to say you can't understand what we mean, its just... you're trying to spell words without knowing the alphabet if that makes sense)? If you don't want to be serious with art and just want to have fun with everything, this really isn't the board to post your work, I'm not saying you can't, I'm just saying maybe this place isn't exactly fit for you (if you don't intend on improving).

I'm not trying to be hurtful, understand, I'm just trying to be honest with you, I personally want you to improve, I'm sure most of us do, I just haven't seen you improve and you keep making the same fundamental mistakes with all your work. Really though, don't take this as a hurtful message, I did not intend it to be, I apologize if you did.