If you want Apple's recommendations on how to preserve battery life, go to the Ipad guide in your Safari bookmarks. You can link from there to the battery recommendations. I believe I scrolled down to the battery parts on the first page and found the links there. I was curious about some saying that you needed to remove the Ipad from its case to charge because of heating. The Apple battery page on Ipad says "certain cases" and one would think that Apple would recommend that to those that bought the Apple case since so many have and all of us have to charge. If I would have to wrangle the Ipad out of the case each time I hooked to the charger I wouldn't use the case long---and I consider it almost a must have for the Ipad. Makes it quite nice to type on screen, nice to carry, nice to hood when reading.
I believe I read that it does NOT charge while connected to computer, but check the Safari Ipad guide