I keep most of my gear like I've always kept my camping stuff, in labeled rubbermaid bins and a duffle bag or two. They're easy to stack, store, and move. As long as the storage space isn't too humid or moist you should be fine. Of course for food items, medication, electronics, and batteries, a dry and mild temperature (50-70F or so) environment is best. Its helpful to figure out what situation(s) you are most likely to face (hurricane, earthquake, etc) and how long you expect to be without basic services (1-2 weeks, 1 month?) and plan accordingly.