Best way to record an emulated game ?

Hey guys, can anyone give me any tips on how to record from an emulator like
. What software do u use ?
. What file do you convert it to etc.
I want to start doing lets plays, I have a capture card but I would like to do some emulated ones hopefuly

I use Hypercam for my emulated games. I then fire it in my ULead VideoStudio and convert it into 15 minute segments in .wmv format.
My Windows XP came with Windows Movie Maker, which is also good for the editing business. If you have that, you should be sound.

I personally use either FRAPS or Camtasia Studio to record emulators, Fraps requires quite a machine and a very high hard disk capacity as it come out to around 1.5 gigs a minute sometimes.

Camtasia is great though, I used it for some of my let's plays and the compression is fantastic, I got a 15 minute video down to about 60mb so it's pretty good.