Since you will be breeding large rabbits for meat ( or so im asumeing

), and depending on what breed you get, they will be ready to breed later then 6 months. You only ever breed small breeds ( such as Netherland Dwarfs) at six months. Bucks will be mature enough for breeding at around 8-10 moths, and does at about 7-10 months. Again, it depends what breed you go with.
To breed the two rabbits, you ALWAYS bring the doe to the bucks cage. If you do the oposite, then they will most likely fight ( the buck will be in the does territory, does are more teritorial), the buck will be too interested in checking out the new cage to bother with the doe etc etc. Never leave the doe and buck together. Some does get very cranky with bucks and will even try to castrate the buck if they get sick of him chaseing her around. So I always where gloves JUST in case they start to fight ( yes we only have tiny dwarfs, but rabbits can do more damadge with their teeth that you'd think

). I genraly let the buck mount and fall off the doe about 3 times, wich just ensures that she is pregnant.
The doe will be pregnant for around 31 days. You will need a nest box for the doe to have her babies in. This will be put in her cage on day 28 of her pregnancy. Large breeds tend to have 5-12 popples ( or new born rabbits) per litter, so there will be peanty of meat if they all survive!
I generaly wean kits at about six weeks old, and then because all of our rabbits are sold ( unless we decide to keep one back for breeding perposes etc), let them go to their new homes when they are eight weeks old.
I would definately recomend joining Rabbit talk ( rabbittalk.com),a forum I have joined that is based on rabbits. There are loads of experienced breeders and people who breed for meat on their, and everyone is very helpful
I hope that helps!