1) The rates are almost always posted, or easy to request from reception - at least at SRM, HFH, Platinum, etc. (no-name Asian places are all over the map)
2) A lot of guys tip on top of whatever the posted rate is - I think a poll once said half do. Me, I never do - I figure the tip is the tip, and the fact that I come back and post good things is the reason for doing a decent job. That, and what a great guy I am.
One more bit of advice - just take the bodyslide. I fucked around for a while when I started with nude, nude reverse, etc., but there's really no way to tell if you're going to like a girl unless you're "sliding". You're better off starting with 30 minutes and the bodyslide than longer with less. SRM is great for newbies - the 40 minute special is $50 at the door and $100 to the girl.
One more bit of advice - read reviews and book ahead. I do walk-ins sometimes now, but half the time it's still an assfuck (in a bad way), even at good spas.
Oh yeah, one more piece of advice - the shower massages and hot tub massages are pretty much a waste of time, as far as I can tell. If a girl's going to be extra attentive and/or offer add'l mileage, it'll happen in the bodyslide.
The hot tub thing to me always seemed esp. disgusting, but maybe that's just me.
Have fun!
And be prepared to blow cash....