And about the floating question...
I believe that she means if you get the betta in a plastic-like bag, you let the bag with the betta in it float ontop of the water in the tank before you actually release him, so the temp. in the bag evens out with the temp. in the tank water.
If you get your betta in a cup (like most do), I find it terribly difficult to float a cup. I just let the cup sit in the room where the tank is for a few minutes, so it sorta-becomes room-temp. Then I just dump the whole cup into the tank.
I'm unsure how others do it, though.
Good luck with your new betta!!