Great post Telepod!
The longest I ever had pollen to work was 5 months. Kept in film containers, mixed with flour in stored in the freezer. But you usually want to use it within the first 2 weeks if kept out.
I'm with tele, I usually like to pollinate my females right around the 4th week, and this way, I still get some nice buds, and it usually gives me at least around 50 to 100 seeds. But this all depends on how big the lady is before I do it. Small clones, around 20+.
If you wait longer during the flowering period, you can get more seeds, but the plant will use all of it's energy to make the seeds. But you'll have alot of white seeds as well, as there isn't enough energy to make them, and this will dramitcally effect potency to some degree, and definitely yield.