PS : Calibration is basically using the battery till the end then racharging it right?What exactly is the point?I've read you shouldn't really calibrate it often.
It doesn't really matter. Even if it's sleeping, it uses up power (albeit not much). So long as you don't plug it into the power socket when you're meant to be discharging, you can do whatever you like.
There's nothing really you shouldn't do per say, but use it without the magsafe every once and a while to just work the battery, like I keep my MacBook plugged in a lot more than I should, because I stopped taking it in the living room when my wireless range went down and it slowed the internet down, but I do still try to 'work out' the battery if you will, but yeah just follow my intstructions and use it as you please in between calibrations and you'll be fine.