There are many, many threads on this topic, and almost as many opinions. The main thing is your battery life will improve after the first week because you will be using your phone less... as it seems like less of a new toy. These are my habits.
I try to charge the battery only after it is below at least 30%, and I try to charge fully and then remove from charger. I always have a backup... currently I am waiting on an extended battery from Seido (sp?), and thus my standard will go in my glove box.
The exception would be if I am using video or GPS, then I will have my phone charging if possible since those drain it very fast.
I use wifi whenever possible and shut off 3G. This has other benefits, like being faster and not counting against your "unlimited" 5GB monthly data usage (or whatever plan you have).
I never have the screen timeout set for more than 30 seconds.
I'm not lazy. If I want to watch a certain video on youtube and I am at home, I will watch it on my computer.
I used my phone a little less than usual today. Facebook, some email, maybe 30 minutes of talk time (on Bluetooth), 20 minutes of gaming. I am currently on track to get about 22 hours/charge