Room treatments and acoustics…. How to begin?

For those who suggested GIK. 

I had sent photos and room dimensions to GIK.  I will admit I received a massive email back.  Was it a plan?  Not really.  There were a suggestions but I found it more conceptual than here is a photo, buy this and place it next to that.

 Am I thinking of this wrong?  I did exchange a number of clarifying emails, maybe I am missing something (always possible) but I think I would have expected/hoped for something more concete?

Appreciate any comments - I ask this, because like the OP I want to know where to start.  And I did start at GIK, which was your suggestion...thanks!

@whyrichard   I would humbly suggest educating yourself first, and a great place to start is with Dr. Floyd Toole's book - it's essentially a text book about the physics of small room acoustics.  Learn the concepts, understand that not all reflections are equal, understand why symmetry is important and that asymmetrically shaped rooms (like your system photo shows) needs asymmetrical treatment plans.  Learn about early reflections, decay times and frequency response, and learn to take acoustic measurements using OmniMic or REW or others.  Then learn how to interpret the measurements or send them to me to decipher for you.  Or send them to GIK.  There is so much to learn especially if you plan on leveraging your architectural background for room design purposes.  It's a journey so pace yourself . . .

I’m nothing more…..How to find first reflection point.

My room is similar in size. I bought GIK alpha panels. I ended up with a lot more than I thought I would. I used the Vandersteen bass cd and a radio shack meter to see that I had low bass nulls after finding the best speaker/listening locations, so I started with their Soffit model stacked floor to ceiling in the corners behind my speakers. That was a noticeable improvement. Then, after watching a lot of their videos, I added 6” Alphas to the first and second reflection areas on the side walls. I still can’t get over what a difference that made to clarity and imaging. I then discovered the bass null was being caused by the rear wall so went with a mix of bass traps on the rear wall and that smoothed things out a lot. My last add was some more 6” Alphas panels to the side walls at my listening position to help with side wall bass null. They have a bunch of new products that are thicker than what was available in the past so you should be able to get some good results. Pick a color combination that you really love, because you just might end up with a room full like me. The panels with the 2D Alpha front kept the room lively, but got rid of the slap echo that was bothering me. Have fun!

Small room acoustics can be the rabbit hole to end all rabbit holes.   I wasted a lot of time and money on this, until I finally followed some really good advice that I will now share with you.  Download and learn to use REW (room equalization wizard).   
In a small room like yours, you are going to have significant issues with room modes that seriously compromise sound quality and with early reflections that will seriously compromise imaging,  

REW will allow you to optimize your speaker position and your listening position to achieve the flattest frequency response you can achieve without added treatments.  This  should be done first.  You will find that the cookie cutter recommendations, (golden triangle etc.) are not optimal.   Once your speaker position and listening position are fixed, next you will want to address early reflections using the impulse data obtained via REW scans.  This will allow your system to fully reach its potential in terms of the spacial presentation. 

Only then should you consider further optimization using room treatments and multiple subs.  

REW takes some time and effort to learn to use and interpret, but trust me on this, without it you are pretty much throwing darts in the dark.  General guidelines and advice from GIK etc is better than nothing, but in my experience, not by much.   It has been my experience that those who learn to use REW do not regret the time invested.  

Good luck!