Congratulations on your new phone and welcome to Android! I love the Infuse. The screen is amazing! You might want to try hitting the Hints and Tips sticky first to get you started.
Infuse Hints & Tips
I started there and it really helped. Also, several of us have posted lists of our favorite apps in here, so that should help too.
There are a lot of posts about extending battery life in here, but I find if I don't run live wallpapers all the time, don't play too many games and use wifi as much as possible that I get pretty decent battery life. I can go about 12 hours with normal use. That drops if I'm on the phone a lot, but still lasts me the day. With a large super amoled+ screen, I think it helps to keep the brightness down a bit. I usually have mine at 30% when I'm not using it. I use "brightness widget" from the market. I love it. It puts a bar anywhere I choose on my screen so I can just slide it up and down to instantly adjust the brightness.
Just ask away when you have questions. There are a lot of real gurus in here to can help. I left Blackberry for Android just over 2 months ago, so I'm still learning too!