1) make sure its as discharged as possible before recharging
2) When charging, make sure you fully charge it
3) if you intend to use it at home with access to AC power, remove the battery first. AFAIK without soldering a switch onto the motherboard there is no way to stop it charging.
My friend kept his on constant charge 24/7 and after a year, the battery now lasts about 5 minutes from full charge.. I did the 3 things above and 3 years on, i still get about 90 mins use from a full battery.