Here are a few links to resources and forums you may find useful
VolksrodsUK Veedub based rodding forum. Allsorts here, lots of practical and technical knowhow and a great bunch of people
BuggyclubUK Buggy forum, great bunch again, some interesting build threads.
BajaClubUK Dont know what to say about this bunch really - words that spring to mind are - certifiable, unhinged, maladjusted... These chaps like to get down and dirty with their dubs. Another great bunch of people.