Probably the reason you haven't had many replies is that there aren't any simple answers. Experienced breeders evaluate the health of their animals on a daily basis, and act accordingly. Noone can tell you: "Well, you can double clutch a female for X number of years before you give her X amount of time off to rest." It would be great if it were that simple, but part of the reason that consistent breeding is a real challenge is that it's not simple at all. Some of it you can learn from books, and the good advice you get on this forum, but some of it can only be had through experience.
My advice? be conservative. Don't try for double clutches right away-learn how your animals react under normal conditions before you try to push them to their limits.
Brad Chambers