I'll sit in the room going over my car well my batteries charge. But I have 1000 watt power supply, a 400watt charger and I parallel charge (charge more then one battery at a time) so I do 4 5000mah 2s in bout 30 minutes.
Storage charge is whats been described, if the batteries wont be used for a couple of days they should be charged to 3.8volts per cell.
Your c rating is important on a high powered set up. I'll use my power system in my Savage Flux for an example. The Blur ESC needs at least a 150 amps to be powered efficiently, so you take your amp rating (mah) and your discharge rating (c) and you multiple them except you need to take out the milli part on your amp rating. I use 50c 5000mah batteries, so 50(c)x5(amps)=250 amps so my batteries are more then capable of powering my ESC motor setup.
Does that make sense I've been told I'm not good at explaining things before.