here and there's several links at the bottom that link to anatomy books, references for master studies, and gesture drawing tools.
The best anatomy books are super cheap (under $10 each) are by George Bridgman. These two are the most helpful.
Then this book for learning how to use colors and light is pretty much my bible. (And it's also inexpensive, under $20.)
Those three books are infinitely helpful. (And you can get them used off ebay for even less, even though they're already fairly cheap.)
Draw from life -- anything around you -- people, pets, spoons, shoes fruit, boxes of tissues, etc. Try to understand the forms and how light is affecting them. How are the colors working? What color is the main light source? What colors are in the shadows? Etc.
Master studies will bump your skills ahead -- Pick an artwork from someone you admire and try to copy it as close as you can -- this will teach you how the original painter used colors, rendered form, conveyed emotion through colors and expression, and it will help you get a better control over your own anatomy/brushwork. You learn a LOT from doing these. Srsly.
You can totally teach yourself -- a lot of the most successful artists I know are self-taught.. You just have to have the discipline to stick with it and do the work.
Now, obviously, I'm gunning to be a professional artist, so my studies are a lot more hardcore because I'm trying to get as good as I can as quickly as I can. This is the schedule I generally follow every day. (Well, I should be following -- I've been a bit lax lately between work and getting ready to move.) It gives a good structure of how to organize your studies that you might find helpful.