Sound on Sound - This periodical is out of England and is really good. Always lots of equipment info, how-to's for various sofware, techniques, etc.  Below are summaries of the various issues I've received.  The first several months don't have much detail but by the time of April, May and June 2007 I got much better at tracking details.
Performing Musician - This periodical is from the same company as Sound on Sound.  Focuses on live sound rather than recording.  Lots less useful articles (compared to Sound on Sound) and lots and lots of ads.
Mastering Audio: The art and the science 2nd edition by Bob Katz - This book is great!
Mastering Engineers Handbook by Bobby Owsinski - This book is great!