Reddit mentions of The First Book of Scales, Chords, Arpeggios & Cadences: Includes All the Major, Harmonic Minor & Chromatic Scales (Alfred's Basic Piano Library)

Read a theory book!!! Take a class!

Go to a used book store and buy a book. Also, you gotta get a basic book on scales and piano technique - I'm assuming you're a piano player - I suggest The First Book of Scales, Chords, Arpeggios & Cadences from the Alfred Basic Piano Library and it's only $6 or so!

http://www.amazon.com/Scales-Chords-Arpeggios-Cadences-Alfreds/dp/0739012975

A theory text book to check out is Music In Theory and Practice by Bruce Benward.... Not sure which edition the book is on at this point. I rather enjoyed working out of that book. I also, highly recommend The Complete Musician by Steven Laitz

Piano makes learning theory a little easier. Piano is a great instrument, but proper technique and theory knowledge is super super super super important.

Listen to soloistic jazz pianists and check out what their doing such as Keith Jarrett or Bill Evans. Their ability to develop ideas and expand on them is astounding. Older cats like Art Tatum would be cool too. My favorite pianist is McCoy Tyner. I reference jazz because of the improvisational aspect of their playing is great.

Also, find a song book by musican or a band or pianist that you really like, and learn the pieces! Take the techniques or things you like from those songs or pieces and put them into your playing. When I play the drums, I transcribe solos or grooves from the greats, and integrate the things that they're doing, into my playing. Copying licks.

A musician once said, "If you can't find something to work on, then you don't want it bad enough". And I think that's true. I think you really need to work on your theory chops though because not knowing the difference between a M7, a m7 and a Dominant is pretty important, and should be touched on.

(Major 7th or CM7 C E G B, Minor 7th or Cm7 C Eb G Bb, Dominant 7th or a C7 C E G Bb <---- The interval between the C and the Bb is a minor 7th if that makes sense)

Music is great, there's always so much to do. I wish I could give more ideas, but I don't know what your goal is, what music you want to play, what your message is to give you more insight.

This might be miserable at first, but if you want to get the maximum amount of development for your composition, I recommend these two books:

http://www.amazon.com/Scales-Arpeggios-Cadences-Alfreds-Library/dp/0739012975

^ This comes with cadences. Learn to play scales, arpeggios, and cadences. All of them.

http://www.amazon.com/Harmony-Fifth-Walter-Piston/dp/0393954803

^ This book will teach you pretty much everything you'll want to know about harmony and composition. Highly recommended.