It is fun, I used to build 1/43 scale cars and race them. Here is a link to the track I ran at. We did 1/43 scale because there are not alot of parts so fabrication and a little trail and error was key. The link also shows pics of bodies Side started making. Good Luck with it and have fun.
http://whitesideracecars.com/Slot%20Car%20Racing.html