A while ago there was a discussion of under layout storage.  This is my solution for under my HO layout.  They are designed to hold magazines on the bottom in file boxes that can be purchased at Staples and other office supply stores as well as homemade magazine file boxes.  Equipment is stored on the top shelf in computer motherboard boxes or the typical rolling stock storage boxes available from several suppliers.  

All storage in my basement is on wheels for easy cleaning and the usual under layout maintenance.