Hearandplay.com
This site has a newsletter. It's really great and every newsletter has lots of great info. The board's also real cool. He sells several courses which seem really good, I don't use them myself tho.
I do believe in teaching in a DIY way. There's a LOT of info out there. Buying books with basic theory or a DIY theory course can go a long way.
What I do recommend is this:
when you practice DIY understand WHY you are practicing e.g.:
scales... if you just play them.. you won't know why and you won't be motivated.
But in order to play chord progressions (which are essential in composing) you'll have to know your scales. Why? You can not play a 5-2-1 chord progression... if you do not know what the 5th, 2nd and 1st tones in that particular tone are (e.g. c = 5th g 2nd d 1st c)
That WILL motivate you.
Also.. finding someone who plays and has a teacher or practices him-herself who's supportive and preferably a bit better than you.. but not yet out completely out of your league to where they'll be bored helping you will also definitely help.
And yes - lessons would be GREAT.. but not the ONLY way to learn.
The very talented young lady I get to call my girl pushes me to get better.. she plays piano (grand piano at her house). When I met her (again.. long story) she was considering stopping music. I was considering getting more into playing. My studiowork and production inspired her to play more.. her playing more inspired me to play more. Now we write songs together.. and I actually OWN my very own piano now also..
Also: playing simple tabs of songs (just go to Google and type in 'Piano tab Rolling Stones Angie' for example. You'll find sites and they've given the chords. It's a lot simpler then reading the music and it's a good way to build up your self-esteem and skills.
Enough tips already? haha. Keep me posted about ur progress - I wanna get as good as my girl man.. I can't front - she kicks serious piano *ss :D