Is your cellar damp? If so, you may have to correct that problem before installing your tools and lumber supplies. Insulate pipes to prevent condensation. Make sure your gutters outside keep rainwater running away from the house. Cracks in the cement floor or walls should be filled with hydraulic cement; a high water table may necessitate a sump pump to collect water at a low point and pump it out. Any or all of these circumstances may also require a dehumidifier. In any case, dampness is unacceptable where power tools are to be used because of the risk of electric shock.
Before you buy a single tool, you need to take a hard look at your workshop space. If your workshop is a freestanding building or empty barn, you can simply measure the perimeter and know that you have the entire square footage at your disposal including the wall space. If your workshop is tucked into the back of a garage or a corner of partially finished basement, you’ll need to plan your furnishings with cars and water heaters in mind.
Unless you’re a big fan of frequent shop remodeling, planning the layout of your workshop early in its development will save you a lot of time and trouble and also can keep you from spending years in an uncomfortable, poorly organized space. And if you already work in a shop that’s as organized as a trailer park after a tornado, careful planning and a little remodeling is likely to help you make a quantum leap.