Here are a few links from the hundreds on the Interent giving advice on how to write your dissertation. Check back soon for updates!
A good explanation and definition of a dissertation with an informative video. Start here!
Dissertation writing from University of Wales, Institute, Cardiff:
This is a straightfoward and easy to understand outline and guide of what a dissertation is, what the different parts are, how long they should be and so on.
Writing up your dissertation from Reading University:
This guide gives study advice from the early stages of planning your dissertation through to editing it.
A really helpful word document walking you through the stages of dissertation writing.
A good clear starting point, and check out the nice simple models they have for the science dissertation and social science dissertation.