Like everywhere else, how long you sit reserve depends on how many come in behind you & how quickly they get there. You can expect approximately the bottom 10 - 12% to sit reserve. For our new hire class (started mid-Apr 07), most of the class sat reserve 4-6 months (on both the 71 & 73). Some of us were lucky to get build-up lines earlier at the 4 month point. Almost everyone from our class will get a hard line in Feb. When sitting reserve, you get a 70 hour guarantee & have 10 or 11 days off (depends on month having 30 or 31 days). Based on current contract you'll get credit for more than 70 hours when you fly. I averaged 85 - 95 hours of pay, with the busy season hitting up to 115 hours of credit per month.
As for hard & build-up lines, all bets are off for intergration. You could work 1 day or 5 straight. After that, you could have any combination of trips (with the exception of standups). There are 1, 2, 3, & 4 day trips. Some back to back, some with nice gaps between, & some have an even flow. The lines average anywhere from min (70 hours) up to 90+ hours. This month I have a line with1 x 1 day, 2 x 3 days & 2 x 4 days for 80 hours. I could have gotten more hours, but QOL is a factor for me. These standups (CDOs) I mentioned are for the min of 70 hours & you fly the the last flight out, get a few hours of rest in a hotel, & bring the first flight back (all while on duty). Some local guys like these. If you are on the 73, we also have red-eyes back from the west coast.