All kind of free theory books. Your library will have stacks of piano theory books. Theory is theory - we then take that theory to our instrument so don't let a book that uses the piano keyboard as an example throw you off. IMO I do not consider reading standard notation as being a part of the study of music theory. A skill that needs to be learned, but, study theory and reading separately. Devote a specific amount of time for each.
Here is something on theory - it's dirt simple and starts with the major scale and ends with how to compose melody. Help yourself. Speed read till you need to slow down.
http://www.ibreathemusic.com/forums/...ad.php?t=11975
Berklee books are excellent and will force you to learn standard notation as that is all they use.
Which ever way you go, good luck.