I am planning finishing my website off once I have finished my university degree and wondered if it was a good or bad idea to put up my final year project / dissertation as downloadable files for perspective employers to read?
If you are proud of it then post as much as you can. It is unlikely that any one will read your entire dissertation, but a prospective employer might browse sections if they are considering offering you work.
Personally I would concentrate on making a showreel and starting to work on as many projects as you can.
After I graduated I had both my dissertation and my final project on my site, as well as a link to them both on my C.V. When contacting pottential clients I used these to show people what I was about. And my dissertation (Sound effects and ambiances in film) was key to getting me one of my first gigs. The director read it and was impressed with what I had written, so gave me the job as sound designer on his short film. Once you start to get some work under your belt this becomes unnecessary as real-world client work will be viewed first and make university work irrelevant. Let the SSD community know if and when your work is up on your site. I'm sure people would be interested in it.