Organizing lumber in a garage can depend on the intended use of the lumber. If you are storing pieces to keep them away from the elements or will not be using them for projects in the near future, then consider using the roof beams of the garage or tops of high shelves for storing long pieces of lumber. Smaller pieces can be stored horizontally in a bin or vertically in a clean trash bin. If you are actively using the lumber for woodworking projects, consider storing longer pieces upright against a wall, using a retaining strap or heavy duty rope to keep the pieces in place. Placing longer lumber behind shorter pieces will allow you to take a visual inventory. Consider the location of your workspace and saws when storing lumber. Lastly, it is a good idea to keep a bin for wood scraps close to the saw or workspace. Have fun!