Rene North's Regiments at Waterloo is a good, but dated (1971) book on the French and Anglo Allied Armies at Waterloo. Friends used it to paint up 25mm lead soldiers for our recreation of the Battle of Waterloo. Unfortunately, as it did not contain information on the Prussian Army uniforms, I was not able to use it.
I would recommend the book as a good reference to the uniforms of the French and Anglo Allied Armies during the Waterloo Campaign.