This is a fundamental question. A good place to start is with a survey of your property. Most municipalities have a maximum percentage of your lot that you can build on and standard setbacks from your property lines that you will need to adhere to without needing to request special permission to build. On a photocopy of your survey you can draw in what your local setbacks are in order to define the location within which you will be permitted to build. In a best-case scenario, you will have the space to build without compromising too much on space or location; otherwise, you may need to request a minor variance, which would allow you to circumvent an obstacle such as a setback.
Depending on your situation, you may need to upgrade to 200 amp electrical service in order to meet the needs of your house and your shop. It may also be in your interests to add in a separate electrical service meter on your shop so that you can clearly write off electrical use for your business, or in future rent the space out and clearly separate out the utilities for billing your tenant. Generally, you don’t want to skimp on the power to your shop or on the lighting you include.
Some of the most important decisions in laying out a shop involve the placement of basic machines, such as the table saw and jointer. Deciding where to put them depends in part on the scale of woodworking you do, which determines the clearance area around these machines if you need to handle long stock or large sheet goods. You’ll also want to consider work flow to avoid an excess amount of running around the shop to accomplish tasks, as well as how to power your machines without turning your shop into a snakepit of extension cords.