I just received a new book called Sidecar Champions Since 1923 by Mick Walker. It is 333 pages, coffee table quality hard cover, published in 2011. Amazing stories and plenty of b+w pictures. I highly recommend it and it has received great reviews.
I purchased it through Amazon.ca and it arrived at my door in only 4 days from the UK for about $30 all in. I was amazed at the speed and the minimal cost of shipping for such a heavy book. There are a number of vendors selling it on that site and a couple on eBay. I used the 4th one down the list at Amazon (I looked at price but also high feedback ratings), "The Book Depository". They shipped it wrapped in a nice cardboard book container.
http://www.amazon.ca/Sidecar-Champions-Since-1923-Walker/dp/1859838103/ref=sr_1_1?s=books&ie=UTF8&qid=1331664982&sr=1-1
There aren't a lot of books on sidecar racing so this is a must have.