Before Installing Storage Units: Building Codes and the Like - Become acquainted with zoning ordinances, deed restrictions and building codes. Depending on your area, you may need a building permit. Building codes may determine how far storage units must set back from property lines and what materials are acceptable for siding.
Organize For the Season - Now that you know what's staying in your shed, you must consider when you use the items. You don't want to move a stack of gardening tools just to get to the snow shovels you'll need in the winter. If possible, dedicate one side of the shed to warm-weather specific equipment and the other to cold-weather equipment. This will alleviate any confusion on where items are and save yourself plenty of time when working.