is the ocforums battery guide. Great info in there, pictures of battery internals.
remove battery when lappy is connected to the mains
store battery at 40% charge and in the refridgerator if possible (do not store in freezer)
fully discharge the battery after every 30 charges to calibrate the charge meter
lithium-ion does not have a charge memory
if possible, don't buy two batteries, but wait till the first one dies and then buy another
don't buy old stock, even if discounted
expected life of a lithium-ion battery is 2-3 years
According to CheesyKing, you can remove the battery from a laptop without worrying about losing BIOS information. If you do this, do what you can to protect the battery port on the lappy from collecting dust.