I'm to cheep to buy books so I go round the inernet to help me with my affects here are 2 pages I really love (I've used hundreds of pages for Info but it would be pointless posting them all here becouse there usually for specific divices,however thse two pages cover quite a large area)

this site has a whole lot of schematics covering a lt of diffrent affects.

and this site gives you the how stuff works aspect (and a couple of circuits to)

hope this helps