I'm a newbie Southwest pilot, so I'll give it a shot:
Pay rates - currently, $50.17/TFP. If we ratify the TA, first year rate goes up to $67.32/TFP. I know TFP (trip for pay) is kind of a weird concept initially, but you get used to it pretty quickly. As a newbie, currently the minimum guarantee is 90 or 96 TFP, and that's if you don't fly up to minimum guarantee. If TA passes, and I believe it will, it goes to day pay - if you are not used - 6 TFP; if you are used - 6.5 TFP minimum or the rigs, whichever is higher. Any pick up of open time, even at straight time, will pay second year rate for the whole trip. Currently, the second year pays $84.65/TFP but goes up to $97.35/TFP if we vote in the TA. It's pretty easy to end up with 120-130 TFP's for the month.
Likely bases - your IOE will be done most likely at the base of your choice. First month of consolidation, your seniority will likely send you to OAK or LAS and maybe PHX. Within 6 months on the line, you should be able to hold any base with the exception of ATL and possibly MCO. Vacancy bids are run every month, so if you feel like hopping bases, go for it. You CAN pick up trips from other bases though - you're not limited to your domicile unlike at most other airlines.
Reserve - depends on base obviously. You can hold a blank line probably after about 4-6 months on the line in junior bases like OAK or LAS. Longer elsewhere.
QOL - if you live in domicile, you're gonna love life. If not, well... roughly 40% of the pilot group commutes. The nice thing is... if you're on reserve and commuting, you'll work, so hotels can be a viable option. Once you have a line, there is A LOT of flexibility with what you can do with your schedule via ELITT (trading with the company), TTGA (dropping/picking up/trading with other pilots, and open time. Nobody I know flies their originally awarded schedule...
Interview - be yourself. It's probably the least threatening interview of all the majors because there's no psychometric testing or simulators or anything like that. You're given a line oriented interview where they'll put some stress on you with a time crunch and crappy options, but that's it. Really no big deal.
Hope this helps... for more info go here:
Southwest - Airline Pilot Central Forums