I know that chins and pulls are part of a back routine. But should I do them on every time I work the back? or should I do chin ups one back day and then the other pull ups?
Both exercises are made to target the lats, so in the end it doesn't really matter. Don't do both though, just use one or the other. You can usually do more chin-ups (palms facing you) and thusly target the lats more effeciently.
you chin should go completely over the bar then back down to lockout on either chins or pullups. yes i would only do whichever one on back day. i do(palms facing away) w/weights hanging from my waist and i love em. when i do them palms facing me, kills my wrists.