Link to PDF worked for me this morning (Nov 6th)

http://assets.red-gate.com/community/books/assets/sql-server-hardware-ebook.pdf

Thank you for the book, I'll give it a read

It's useful for any DBA who wasn't initially involved in the server hardware plan/purchase (me), especially if you have someone else or Windows team to handle that

Also keep in mind, CPU cores will factor into SQL 2012 licensing 🙁