The installation of Paddock is not quite intuitive. You need to rename some files, change some variables and add the table structures to the database by hand. I know this immediately scares off a lot of users, but hey, it was originally made for a friend of mine from the Dutch Racing League and I didn't think someone else would want to use it. :)
To help more people setup paddock, I've created a page for it with a FAQ! It explains all the issues that people mailed my about. If you still get stuck, please don't hesitate to mail me about your problem; I'd love to help!