737 and 320 training is 25 days with the on-off schedule that EMBFlyer described. E190 and S80 is 33 days with a similar schedule, but they have an additional week of ground school (737 and 320 have computer based training beforehand that removes the need for that extra week).
Everybody has 48 hours off after their sim checkride, then they have an additional 48 hours to complete four observation rides in the jumpseat of their aircraft (two of which they can do as early as completion of their 5th sim).
Then you are blocked days for OE (Operational Experience – flight with a check airman to make sure you’re up to speed). Domestic pilots get 18 days, international pilots get 23 days (international pilots also do a couple days of additional ground school). You need 25 OE hours, and it’s normally done as two trips of 2-4 days.

During a full month of training, you get the Monthly Average Line Value (MALV) for your four part bid status (ex: LGA 737 Domestic FO). This varies month to month, but it’s usually around 80 hours paid at first year pay (about $85 an hour right now). On your last month of training as you transition to reserve you will be paid reserve guarantee of either 73 hour for long call or 76 hour for short call. On the rare occasion that guys come off OE and hold a line, they get prorated daily value of MALV while they’re in training, then the value of any trips they pick up when they’re done with OE.

Your base and aircraft are determined on day 2 of indoc. The class is arranged by birth date and they pick from oldest to youngest.