Hi,
There is plenty of research on the analysis of rugby... many research congresses have been published - try looking for 'science and football' papers. Alternatively Notational Analysis of Sport (version 2) by Mike Hughes (the godfather of analysis!). These should provide you with plenty of information and are (i think) available on amazon.
If these don't have the biomechanical information that you want, a trawl of the biomechanics literature/journals should provide you with some relevant stuff, perhaps from other sports (such as cricket/baseball/softball) with techniques similar to those in rugby union.
Systems such as Silicon Coach/Dartfish/Quntic are commonly used for biomechanical anlayses, however alternative systems such as Focus X2/SportsCode/Match analyser, are used to 'tag' clips of video so that you can organise them and/or generate match statistics. Obviously depending on what you want to do, each system has its benefits.
The alternative to all of that is to employ someone like me to do match analyses for you!!!!!
www.thepac.co.uk
Good luck!