Well...the water temp varies from fish to fish...but generally high 70s are best. Here's what I did to cycle my tank:
I set everything up and let the tank run for a few days...then I went to the store and bought some 12 cent rosy reds (feeder fish) and plopped them in there and took care of those for several weeks...but you can buy something that you actually like...just make sure they are hardy first.
After that you can add a few fish, maybe once a week. (this is very important, you don't want to put too many in at once.)
The most important thing you can do is go out and buy a testing kit for ammonia, nitrates, nitrites, pH, etc. Most of the time when a fish dies and their owner comes online wondering why, its because they didn't have a test kit to see that their ammonia/nitrite/whatever level was at a poisonous level for their fish.
AND! Pay careful attention, now. Do not overstock your tank. Go to a fishy website or google the types of fish that you want and look at their minimum tank requirements. Don't get anything that requires a tank bigger than the one you have right now. The general rule of thumb is one inch of fish (its full grown size, not the size it is now) per gallon. But even that is flawed, as some fish make more of a mess than others, and require 3-4 gallons per inch (like my oscar.)
And stay away from plecos. Alot of people buy them thinking they'll clean up the tank, when really they make more of a mess than they get rid of (and they get over a foot long...which is way too big for your tank.) If you want a clean up crew go for some little corydoras or something.
Hope I helped, and good luck with your tank!