Be sure to activate any kind of Long-Exposure Noise Reduction feature your camera may have. If you have long star streaks, there is no way that you have nice sharp stars too. Those sharp stars aren't stars, but rather noise in your image caused by your sensor. This is where a quality camera body comes in handy!
Prophecies, thanks for the info man, yeah im quite new to photography besides your usual point and shoot holiday stuff, so this is quite a fun learning experience. I just recently learnt about the need for countering the rotation of the earth after a few test 10min shots. Besides lightpolution i had a ton of streaks, but…
@ JohnnyRaptor: Astrophotography can be ridiculously expensive, what with the cost of equatorial mounts. You're going to need a solid tripod, and a mount that will factor in the rotation of the earth, otherwise you'll get long star trails with your long exposures. This can be a good thing if it is the effect you want, but…