Hi guys, (I need some help

)
Now that I'm starting to get my system "squared" away...I really think it's past due that I start looking at treating my room. Because I share my audio room with the rest of my family (as the living room) I would like to make temporary treatments. Something I can bring out...or set up in a few minutes during "listening sessions". After I'd like to take these treatments down and store them out of sight. This isn't to say I don't want the treatments to look nice...because I do. I also know there are advantages to having the system in a dedicated room. Even tho those of you who may suggest this are right. This is not an option I'm willing to do. If I had a larger house and more money...I'd love to do it. But, I can't. I gotta work with what I got.
While my system does sound pretty good. I do know the room needs some help. But where do I start? How do I determine what needs to be done? and what needs to be done first.
I could post some pictures of the rest of the room if needed...actually...give me a couple days and I'll get some in the gallery.
The room is a multi-purpose living room which makes use of not only the audio system but also a wide screen Tv between the speakers. The size is 15' x 20' x 9'. The system is set up on the 20' wall. While facing the "system" wall there is a brick fireplace to your left, the other wall is open to the dining and kitchen area. The walls and ceiling are drywall normal construction. The floor is hardwood with a large area rug which covers nearly all the space from the front of the speakers to the listening position. The listening position is about 10' from the front of the speakers. The speakers are currently about 2' out from the rear wall...and 15" out past the Tv. Behind the listening position I have a bunch of glass. One french door and several windows to each side of that. Currently we have room darkening/insulating blinds covering all glass.
Well, that's about it. Any idea of good places to start? I can't do everything at once...so what would be a good progression?
thanks so much!
dan