I'm planning to host my first cash game in a couple of weeks (I've always hosted tourneys), which should be a fairly casual game with some players who are fairly new to NLH. I'll most likely do .25/.25 with a minimum of 100 bb buy-in (should I set a max?) What are the generally accepted rules for rebuys/top-offs in a "casual" game like this? Should I allow rebuys at any time, and for how much?