Welcom, Silverlil! I have used a number of methods to display my tie-dye in a 10 X 10 space over the years. My first method was to suspend dowels from the cross-pieces of my canopy framework, using large 's' hooks. I then hung the shirts using clothes hangers, or threaded the dowels thru the sleeves of selected samples for eye-appeal, then stacked the folded shirts on tables. Then I added hanging racks. First, I got some 'closet organizer' racks from Wal-mart, but they weren't very sturdy. Last year, our J.C. Penney store was remodelling, and for a really inexpensive price, I got 2 display racks, each with 4 adjustable hanging bars. They can be unassembled for transporting to the craft fairs. Try searching the web for clothing display racks... here is one I have shopped at:
http://www.fixturedepot.com. Many larger communities have display resale outlets where you can get good bargains. Here is a picture of what I have, just to give you an idea:

As for giving written instructions, you can, but I usually don't. At one time I had cards available to customers who asked about care, and just gave them one. I think it's up to you if you want to...
Happy dyeing!
Judy