nfg,
Congrats on the interview. I'll try to answer your questions:
1. On reserve, you get 10 days off per month. You bid for 4 "golden days" off, which are days which you can't be made to work. The other six days can be moved. You'll ususally do 5 on 2 off, with one 4 day stretch in there. The biggest complaint I've heard about reserve is that there is no seniority based call out. How scheduling calls people is completely random. You may fly every day for a week, then not at all for a month. I've done my fair share of reserve here, and it's not as bad as most people say. If you live in base, I think it's cake. If you plan on commuting, then it's a little tougher.
2. Getting off reserve is hard to say. Right now, junior lineholders in DFW are around 13 months, while ATL is around 2.5 years. However, that means absolutely nothing when it comes to what it might be in the future. We actually shrank in 2003, so people hired in the end of the last wave are seeing lots of reserve. I'd say if you're hired in the front of this cycle, you'd probably see a line in 6 months-1 year. Could be less(DFW), could be more(ATL).
3 Commuting on reserve sucks. Lots of people do it, but it's not the easiest since your days off are limited. I'm not sure what you mean by "when do you usually start your day?" I've been called at 5am or 9 pm, and everything in between. Reserve periods are 15 hours long, so usually as you get later in your reserve shift, it's less likely you'll get called.
Hope that helps. Good luck with the interview. If ASA gets some more airplanes for 05 & 06 you may be getting in at a good time.