The foundation of the set of basic tools should be the carpenter's tool pouch. Buy a leather one with two pouches and a separate hammer holder. Add to the pouch a tape measure that's at least 25 feet long; a speed square, shaped like a triangle and only 7 inches in size; a chalk line, which is a device that holds a line encased in powdered chalk; a chalk line clamp, which enables only one person to drop a chalk line; a one inch wide chisel; a flat-sided carpenter's pencil; a framing square, a L-shaped piece of stainless steel or aluminum; a retractable utility knife; a cat's paw, which is a nail digger, usually with one curved side and one straight; and a 20 to 24 ounce hammer.
Add a hand saw, a 4-foot level, a set of regular and Phillips head screwdrivers, a small pry bar and a 7 inch pair of nippers to round out your basic tool requirements. Protective eye wear is always helpful. Expand your arsenal even more with tools to make any job easier--a stud finder, laser level, and an 8-foot stepladder.
Top of the list are a power drill/screwdriver combination and a circular saw. A power sander is great for blasting through sanding projects. Make sure to use the proper heavy-duty extension cords.