call me lame, but there's a book called "The Atlas of Middle Earth" 2nd edition by Karen Wynn Fonstad. It's very informative of the battles in all of lotr, including the silmarillion and the hobbit. It also has maps of different places such as the barrow downs and lothlorien... it even has troop number estimations for every battle.. and shows on a map where troops were stationed and how the battles went. if you are a big fan like i am (obviously) you should buy that book.