If I had it to do all over again, I would pollinate 1 week after the first hairs show up. Each white pistil (hair) is a potential seed. If you wait longer you can get more seeds, but you run the risk of a lot of them being immature and worthless.
Keep in mind also, that a male will not be ready to pollinate to his fullest until he is about 5 weeks old or more whereas a female may be ready for pollen at 3 weeks. I would try to get a male that is 2-3 weeks older than the female in that case, so that the male has plenty of pollen to throw around and you get full coverage.
Of course, if you just want to pollinate a branch or 2 and not the whole thing, you could use a much younger male plant. I believe males AF strains are typically tossing pollen for the first time around week 4 on average. Using some of that pollen on just a branch or 2 should still let you get a few seedless buds, and also a few seeds for stock.
If you want to get as many seeds as possible, wait till the male is 5-6 weeks and shake him over a 4-5 week old female. You will get some seeds that dont fully develop, but you will get a TON that do. I got 472 seeds total from 2 Diesel Ryders that way. One was 5.5" tall and the other was 6", so that shows the possibilities when pollinated a bit later.
Hope that helps
KB