Of the links listed below, some are relevant to my dissertation, while I can recommend some personal favourites. An interesting site used in my dissertation has unfortunately disappeared off the face of the net - the "New Zealand Rugby History"(formerly available at www.vuw.ac.nz/~pjpower/rugby.html) seems sadly to have disappearred.

Rugby-related dissertation links
IRB official site The International Rugby Board's website. Site includes press announcements, a law-book and an interesting list of the numbers of players and coaches in every rugby playing country. Fascinate your friends with gems such as "Did you know that there are 880 teenage rugby players in the Czech republic?" (Or better still, don't bother!)
Myth and Reality in the 1895 rugby split Analysis into the "great schism" of 1895, written by rugby league historian Tony Collins. The piece is strongly pro-league and anti-union, an apparent pre-requisite to rugby league journalism (e.g. Dave Woods, who writes in The Independent, being a parody of this type of RL journo), but it's nonetheless a thought provoking and worthwhile read.
The New Zealand Natives' Rugby Tour of 1888/89 Fascinating insight into the largely forgotten tour which paved the way for the more famous 'Originals' Tour of 1905/6.

Other rugby sites
Planet Rugby

The ultimate rugby resource - a constant supply of breaking news from all over the rugby-playing world, columns from prominent rugby writers, competitions, and a huge archive of historical rugby information are among its features.