Here's the first star trail pic I ever did! I much prefer the one that I took that I put in the first post of my blog, as it has cool scenery in it, but this one turned out better in my opinion. The difference between the one here and the one in my first blog post, is that the one in the first blog post had the Full Moon out so it looks like day time in that one, while still being able to see stars!
This was done as a long exposure with the camera pointed at the north star, Polaris. All stars appear to rotate around polaris due to the Earth rotating in space. Stars closer to Polaris move in a very tiny circle, while the ones farther away make a huge swoop. I had to cut this off early as the clouds started rolling in as you can tell :)