firstly congrats on getting an awesome phone

Ive not got the n96 but ive got a n95 8gb which is pretty much the same phone really.

What you should do is just use the phone out of the box as it should have 2-3 bars of charge already? use it until its about 1 bar or starts to give you the low battery warning beep and then turn it off and charge.

Whatever you do dont let the battery completely run flat until the phone cuts off as the battery isnt like the old type where by draining it is better, its the opposite with these phones, just make sure its turned off and on charge BEFORE its cut off and you will pro long battery life.

Enjoy the phone, i know iam and im still finding new things even after owning it for a month