I reccommend seeing the movie Bloodline, most of the material in the first parts is old news, but it gets interesting when he meets up with Ben Hammott and discusses his discoveries of the Templar Tomb hidden in a cave that he found by reading clues left by B Sauniere.
Hammott has released a book titled 'Lost Tomb of the Knights Templar' which is affordable through his webpage. Amazon is asking a very high price for the book, but it is only fifteen pounds through paypal. There are strange type-o's in the first printing of 'Lost Tomb' and I can't help but wonder if Hammott has left a encoded message in the pages. ;)
Anyway, I'm about halfway through the book, it's got some great insight into the local life and natives of Rennes-le-Chateau and lots of info about what icons and artifacts can be found in the church and what's in the museum.
(I think most of the key points of the documentary are now on Youtube.com)
and since it's the time of year- happy Beltane