I use 15 grams before I train, 10 grams during my training and 15 grams postworkout! Giving 40 grams total around workout time....BCAA's are probably the best supp I've used, very anabolic! Research has been done that proves 40 grams around workout is ideal!
BCAA's are a 2:1:1 ratio of Leucine:Isoleucine:Valine. Its also been proven that you can benefit further if this ratio is 4:1:1, so if you can, get some extra Leucine powder and add it to the BCAA when you take them. Quanity wise this works out to Leucine being half the amount of the BCAA quantity!
So for example:
5g BCAA requires 2.5g of extra Leucine to create a 4:1:1 ratio.