I've read that it is best to take them on an empty stomach. Better absorption.
As for when, pre and post workout is the most important times.
I also take very large amounts DURING my workout when I'm dieting for a show. Really helps preserve the muscle mass.
you need about 20 gm each time you take them in the day if your around 200pnd.
so i take 20gm pre and immediatly post workout or my last set. then 40 min lateri take my whey/carb drink. the aminos i use are assimalated in 10 min. i get them at infinityfitness.com
No real estimate just the fact I want protein in my system at all times. After a high protein meal you flood the system with protein but then it falls before the next. I feel that if you use a few grams every hr you will better be able to stay in positive nitrogen Balance