Every breeder is differant but breeding weights are 45 grams and higher. I don't breed under 50 grams personally. Also make sure you have somewhere to house the hatchling. They are very fun to watch grow up as their patterns and coloring change.
The best thing you can do is read alot of the post about breeding, incubating and hatchlngs. It will be alot of reading but you will find alot of helpful info.
and it's per breeding season, which generally lasts from February to September or so (but we have females begin in November/December because it's so warm here)
here is a chart that estimates the number of eggs per female, based on age. The contents of this table were taken from Wikipedia ("leopard gecko" search)
This is JUST an estimate. We have a female that is 1 years old and produced 4 clutches (8 eggs) so far this season. We have a 3-year-old that produced 5 clutches (10 eggs), and each clutch was laid every two weeks, scripture. We had another 1-year-old that laid one infertile clutch and nothing else, and another 1-year-old that has laid two clutches so far.
Yes, your female only has to breed once a season to keep producing fertile eggs. I heard about this so I decided to test it. I waited till my female was gravid then removed her. She laid her eggs. Then a few days ago she laid another clutch(still by herself)