I've been reading about workout routines, and one thing I've noticed is that they all assume that I already know how much I can lift, and honestly I haven't got the foggiest. For example some routines recomend just a few reps with weights near the max, and some call for lots of low weight reps. My question is: does anyone have suggestions for finding what my max is, and what is "low weight"? I'd assume trial and error is the only way, but how much rest should I have before each trial (as obviously if I try something it's going to affect each successive try)