Another neat way to store stash if you don't have a lot of storage space (ie shelves) is to use skirt hangers - the kind with the two clips on each end. I use these for FQ's and other shortage yardage especially those that have "chunks" cut out of them. I keep them sorted on these hangers by color. I can easily flip through my FQ's on the hangers to see if it holds a fabric that I want. And a bonus is if you find the skirt hangers that have 5-7 different hangers on them in a vertical line. SCORE! I've got one or two of those.
With regard to ironing, I don't iron any of my fabric after I pre-wash/dry it until I'm ready to cut it. Folded fabric is going to have at least fold creases so I'm going to iron it anyway IMMEDIATELY before cutting. Why do it twice?