Ron Oglesby and I wrote a book about Terminal Services for Windows Server 2003 last year. We're happy to announce that this book is now available as a free download in either PDF or CHM format. (CHM is the Windows Help File format, and I personally like it better than a PDF for large documents such as books. It's very hierarchical and easy to navigate.)
The book is "Terminal Services for Microsoft Windows Server 2003, Advanced Technical Design Guide," published in 2004.
You can download this book, and my other MetaFrame books, from the books page at https://www.brianmadden.com/articles.