In the movie "Gran Torino," Clint Eastwood's character said: "Take these three items, some WD-40, a vise grip and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone."
I asked a local fan of do-it-yourself home projects to list the top five must-haves in any toolbox. He said, "A drill, hammer, jig saw, tape measure and an adjustable wrench." It was painful to see how much he wanted to add to that list.
It's recommended to start out with a basic assortment of tools, which, in addition to the above, might also include a screwdriver set, pliers, a level, utility knife, work light or flashlight, electric drill and a hacksaw. Of course, don't forget the toolbox itself; you would not want to have to hunt around for your tools in an emergency just when you need them. A toolbox will help you keep them in one convenient spot. There are also crucial items for safety, cleanup and convenience to include in your toolbox, such as safety goggles, work gloves, rags, a pencil, superglue, duct tape and WD-40 (a form of anti-corrosion and lubrication spray). You will be able to accomplish many tasks around your home with the above list.
Build your tool collection as you find the need for more tools. This way, you can accumulate a large assortment of handy tools without going broke. When you can, buy sets and interchangeable parts (screwdrivers, drill bits, adjustable wrenches, etc.), but never forgo quality. Broken tools will not do you any good. You will most certainly need a variety of sizes of screws, including Phillips, Robertson and standard heads. Some tools can do double duty. For instance, you can use a pair of vice grips or locking pliers in most cases where you would need a clamp. For normal house repairs, you will probably only need SAE (standard measurement) tools such as sockets; for most automotive work, look for metric sets.
Other useful items to add to your toolbox include a level, preferably one at least 1 foot long. This will help you when you are hanging pictures or installing shelves and anything that you need to ensure hangs straight; there are shorter, longer and electronic levels, but the 3-foot tool will do quite a few jobs. A putty knife with a 2-inch blade will come in handy when painting, scraping away dried paint and cleaning up putty jobs in the bathroom and around pipes. Utility knives with retractable blades will help when cutting into wallboard; just make sure you have a supply of spare blades. Power sanders with varying grades of sandpaper and a shop vac with an internal bag to catch fine dust particles may also be useful.
All lengths of retractable tape measures will be handy, but having one at least 25 feet in length will be helpful when measuring room sizes; make sure you have a locking feature, the tape blade at least 1-inch wide and a tab at the end that will hold onto the measuring point. Both 8-inch needle-nose pliers and 10-inch groove-joint pliers will have use around your home; the groove-joint's wide jaws will work on most plumbing jobs. Straight edges and cutting squares will keep you "within the lines," and files will help to trim the cut edges. Corded drills will handle lots of heavy work, while cordless are portable and can be used whether near an outlet or not. Add in wire cutters, a stud-finder, and a pry bar and very little will stand in your way. A sturdy pair of sawhorses will help you put a worktable anywhere you need.
If you are not sure of what you (specifically) will need in your toolbox, it is good to know what type of work you are willing and capable of tackling and what kind of work you would rather hire a contractor to do. Go to the website of any large retail hardware store and you will be able to find many guides on tools and their uses. Remember to start with the basics and build from there as necessary. Do-it-yourself projects can be both fun and complex; be sure to keep both your comfort level and your pocketbook in mind.