how to care for battery in non-unibody macbook pro

I have a non-unibody 15" macbook pro 4,1 running 10.6.8. i'm not sure the year it was made [is there a manufacture date anywhere on the machine?].

the included battery finally completely died on me 4 days ago and i ran it solely off the ac power until yesterday, when i got paid and bought a new battery.

aside from calibrating the battery [charge to 100% -> discharge to sleep -> recharge to 100%] as the first thing, what can i do to make this battery last me a long time?

the internet seems to suggest that the machine should generally be left plugged in if near a power source- basically, nearly all the time. is this true?

assuming it is true, how often should i exercise the battery and how much? i should run it down for what percentage per day or week?

thanks!