Room Treatments - Where to learn more?


Can you suggest some links to websites with practical advice on how to improve the acoustic properties of stereo listening rooms?

I'm about to do a major upgrade to my mediocre system. After reading Robert Harley's "High End Audio" Chapter 4, I gather that room treatment should be near the top of the list for areas to work on.

This is probably especially true since my room has so many hard surfaces.
Picture of my Room
Suggestions on practical ways to improve the sound of my room would be welcome. My thought for the first step is: install drapes on all those windows. The room size is 21 x 22 x 8 feet with 3 open extensions into other spaces.

What else would you suggest for me?
What has worked for you?
hdomke
Fishboat,
Thanks, the link to Ethan Winer's PDF was excellent. It is called "Acoustic Treatment and Design for Recording Studios and Listening Rooms" and is packed with good information.

However, I'm still looking forward to reading the "Master Handbook of Acoustics" 3rd edition which is on its way to me now from Amazon.com

Today as a first step, I hung a Pendleton Wool Blankets on the back wall of my listening room. It may not be as effective as Owens-Corning 703 Rigid Fiberglass, but it does look nice.