any good sites about form during exercises

[igunick]

Do you guys know any good site about form during exercises???
Because I'm starting to doubt my form during a lot of exercises. This all started since a trainer at the gym said my knees shouldn't go past my toes when doing squats. I don't know if it's true since I have never heard or read that anywhere before. But if it's is, what other exercises have I been doing wrong then?

[austintwo]

try exrx.net for starters - I'm sure there are others, but this is a great starting point