Hi fellow Canuck, I did this quite a bit with my F4s, but that was a while back. it's pretty easy. First find some place dark, no city lights. Set your camera on a tripod, I use to point the camera at Polaris, the North Star, with a cable release I'd lock the shutter open and go have a few beer.
When I thought it was long enough I'd close the shutter and point the camera some place else and do it all over again. Got some pretty neat stuff. A big bonus is if you can get an airplane, satellite or a meteor pass by, bigger bonus of coarse would be a ufo but good luck with that.
as for which lens, I believe anyone that you have will work, just set the focal length for what you want to cover. As for aperture if I remember right I would use around f8, but might be wrong. This is a good place to experiment, it's not a one time thing, the stars have been there for 14 billion years and I'm sure they'll be there tomorrow night.
A moonless night is also a good thing unles you want to shoot the moon. hope this helps, and don't be afraid to show us how you did, and keep looking up.
Swede