I plugged that baby right in and started downlaoding and setting it up the way I like!!!! I have never charged a phone for 8 hrs before use. The HTC charges fully in less then 1 hr and that is all I did!
My understanding is that it's no big deal to use it/charge it whenever you want. I wouldn't think twice about using it while charging it the first time.
About once a month, you should let the battery drain all the way and then charge it fully. This apparently resets the battery monitor to give you an accurate reading. Usually, though, it is better for the battery if you don't run it down all the way before charging.
In general, use it however you like. Batteries are robust these days and cheap enough to replace if you need to. Have fun!
lol, there was no way I could have turned it on it let it charge.. I turned it on and started download apps