i never studied music theroy, so what i wnat to know what really is it, and will it help my playing?
Not at all. It only helps in understanding and writing.
definatly, songs become easier to learn (especially if you like most peeps have relative pitch rather than perfect pitch), your improv and compostional skills will improve you`ll be finding chords and arpreggios without thinking about them etc etc.....
Well its spelled theory. There's a start, maybe you can work it out from there.
Music theory is the basic guide lines to music (although it is alot of information and can get complecated). Can it help your playing? Well, yes and no. It will help your improv and music writing and it can help your technique and skill but playing songs or practices can help your technique and skill also. Is it important? It depends on the person. I'm taking a high school course on it just because I want to learn it and develope my writing skills. Others might not needed, people like Jimi Hendrix managed to write great song with little knowledge just but listening to the notes.
Check out some of the stickies in the Musicians Talk subforum, and if you have any specific questions, they'll be much more helpful than Electric Guitar, I'm sure.