This is a pretty good resource:
YouTube - 08 Ninja 250 Chain Adjust Clean Lube
Met's got a lot of good points as well.
Personally I only lube the chain when it needs it, when I start to feel it getting rough, it squeaks or pulses.... Maybe every 600mi, and after every rain/snow....
I try and always work on a warm chain, cleaning it with a Grunge brush and WD40, adjusting it proper, and then riding it for a solid 10 miles to immediately put it up on the stand and shoot a light coat of Belray Lithium chain lube on the inside of the chain. Two things will happen, the chain lube should bubble and get sucked into the crevices of the chain, and the chain will become absolutely quiet. If it's running with the rear on the stand, it also won't oscillate at all... Hope this helps.