To help save battery life I have been using
Scripts | 10/03/2013 | Team Kernelizers | Operation Killjoy™ | RC7 | Insanity - xda-developers it helps speed up some functions and makes it sleep better so it uses less battery when not in use but the device is still on. You have to have a recovery manager installed to use it though, so you might as well root it at the same time.
Lux brightness is another great app that manages screen brightness and allows you to set it based on ambient light how you want it and not just at factory settings. The great thing is that you can use the camera to adjust it if there is not a light sensor. Also it can dynamically change it or just when you turn the screen on.