I had a chance to grab a copy of the Pro LCS Live Communications Server Administration book from Apress recently. I tend to get a lot of emails asking for recommendations for books and training so when I do get a chance to read a good technical book, I want to get the word out. I did read through most of the book (about 95%) and absolutley recommend it to anyone who is planning to deploy LCS 2005 or has deployed it and have questions on some of the configuration options / settings. Another thing I like about this book is that Rui Maximo is one of the authors (I believe he wrote about 70% or more of the book). Rui is a Senior Program Manager with the LCS / OCS group and has been working on this product since its inception - he really knows his stuff! I even had Rui sign my copy during Tech Ed 2007 in Orlando this year.
The ISBN for the book is ISBN: 1-59059-936-9 in case you want to order a copy for yourself (unsigned though).