i do the exact same thing. after reading so many stories of people going to the hospital from dropping their carboys, i decided to go back to plastic buckets for a two week primary, and kegs for secondary/serving. i feel much more comfortable about it now.
as far as temp and pressure, that's up to you. i would say the upper limit would be mid 70's, but hopefully lower. keep the beer in a temperature you would normally feel comfortable with it. keeping it in a keg is no different.
as far as pressure goes though, you want to purge all the oxygen out of the keg before you transfer, and then make sure the lid seals. if you have a keg in good condition, you won't need pressure to seal the keg, but many of us, myself included, have kegs that require pressure to seal.
that is if you only want to secondary in the keg. many times, i just keep it on pressure so it will slowly carbonate that way over the course of a couple weeks.
this is just what i do, and by no means is it the only way. figure out what works for you in your setting the best - this may take some trial and error, but you'll figure it out soon enough. don't be afraid of trying new things too.