Firstly, 414m2 is talking about NiMH cells when he says "dont store them discharged". If you're running nicads, discharge them to 5.4v or 4.8v or whatever and store them.
Discharge till its 4.8v and you cant go wrong....just dont leave it discharged for too long....like months or your cells will reverse...more likely in nicad.
Not sure what the hell he's on about here, but...
With NiMH cells there's a hundred different ways of treating your cells. Pick one and stick to it. Most guys either discharge to 5.4v and store it till next run (same as a nicad) or discharge to 5.4 and put 20% charge or so back into the packs then store it.
Some guys like SMC (
http://www.smc-racing.com) recommend completely flattening your packs then dead shorting them - which goes against everything anyone's ever believed about r/c NiMH cells - but this DOES give you better voltage, at the cost of runtime! (ie runtime will decrease). This is generally used for stock racing. This will decrease the lifespan of your pack most likely though. Really only recommended if you know what youre doing.