The most important advice i can give you is to listen to other soundtracks. I listened to the Tekken OSTs then I immediately got some crazy ideas. Also you need to learn scales, the cool thing is; they really are not hard to learn. If i were you I would visit this address: http://www.looknohands.com/chordhouse/piano/
It has every scale and every known to man (maybe a few known to Martians).
Also if you are serious about music, then you wont mine putting a percentage of your paycheck into it. You might want to buy some instruments so you can learn them. Or some software and hardware. I cannot give you specifics because I have a low budget setup myself. Go visit emusician.com, they have plenty of articles that will make you better.
You need to understand how other instruments play. I looked up solos from many different instruments, as an end result i learned some cool licks that i integrated in my music.
You only need to learn BASIC music theory to compose. I couldn't teach it to you, but google is your friend. You have to be hungry for knowledge and search for answers. This may be a little cliche however: no matter what it is you are doing, you cannot give up. I always seem to be in producers block, but I get out of it eventually.
Keep up the good work, Peace.