You don't need the calibration, batteries in small mobile devices don't have the battery gauges found in some laptops.

But other than that, do as ossipena said: Charge it to full, when it's full it's full. There's no trickle charging like there used to be with old NiMH batteries.

It should be sufficient to run it down to not more than half the first time, then charge it again. After that just keep charging when you get the chance.

Try to avoid deep discharges as the plague, every single one of them you run into will reduce the capacity and shorten the lifetime of the battery.

[There's actually an exception to li-ion devices and the long initial charge.. some Sharp Zaurus devices needed an initial 24 hour charge, not because of the li-ion battery, but because in addition to that they have an extra NiCd battery which keeps the device's RAM (the part that works as a storage area for applications, i.e. your installed stuff) alive when removing/replacing the li-ion battery. Our Nokia tablets have non-volatile storage and doesn't need this, so no extra NiCd or NiMH battery and thus no long initial charge necessary.]