I just got "done" building a barn. The barn isn't finished yet... but the plans are firm as to what it WILL be if it ever does get finished. We had a contractor build the "shell" of the barn and the rooms for the tack and feed rooms, but we are left to finish the inside of the barn by ourselves.
Cherry Hill has a book called Horse Housing
that is very helpful. It goes through just about every detail of a barn you should consider. She also has a DVD called "Your Horse Barn" that essentially has the same content as Horse Housing
. I borrowed the book from the library, but I bought the DVD. I have went back to it for reference several times in my planning process.
I drew out several, if not a hundred, different floor plans. You can use graph paper or do it digitally. Think about how you need to have the barn placed on your property, wind patterns, and water drainage (if you don't have the means to correct the terrain to fix poor drainage). After I decided on a floor plan, I actually built the barn in Google SketchUp, which allows you to "walk" around inside your buildings.
If you are able to build an indoor arena with the barn, I don't see why you have to wait. It might be easier on your nerves to only have one project going on at a time. If the barn is built first, then you can see how the traffic flows in and out of the barn, and determine a good place for the indoor. If you want the indoor to be connected to the barn, it would probably be easiest to build them at the same time so there's not a problem with connecting the two buildings.
One thing I recommend... If at all possible, have a contractor or building crew finish the job. Chances are if you leave anything left to you to be finished (a large project - such as putting in stalls!), it may take a while.
Here is a link to the Horse Housing
"Your Horse Barn" DVD: http://www.horsekeeping.com/videos/Y...seBarn-DVD.htm
Chances are if MY library had the book, yours will too - or be able to get it on loan from another library, as mine did.