Not quite, but the first step is to clean up the damage. To do so, start by enlarging the area around the hole until the surface of the sides is no longer uneven, soft or cracked. Using your fingers, pull out the loose pieces of wallboard. Then take a utility knife (a steak knife will do in a pinch), and cut out a square or rectangle around the wound.
Measure and cut a piece of scrap plywood so it's 2" longer on either side than the width of your hole. We're going to use this piece to anchor the drywall patch in place. If your hole is larger than 10" on its longest side, you'll need two pieces of scrap plywood to anchor your patch. Insert the plywood into the hole, inside the wall. Pull the plywood flush against the back side of the wall with one hand and hold it steady. While holding the plywood in place, use a cordless drill to drive a drywall screw through the wall making sure the screws penetrate the drywall and then bite into the plywood piece. Do this on both ends of the plywood piece. Be sure to sink the top of the screw into the drywall so you'll be able to hide the repair.
If you're trying to match a smooth wall finish, it sometimes helps to put a piece of thick paper (like construction paper) between the plywood anchors and the back of the drywall. Then cut out the paper where the new patch will fit into the hole. This will allow the new "patch" piece of drywall to sit below the surface of the wall being repaired. As you build up mud to cover the hole, the patch will not bulge out beyond the original surface. Then you can really work on sanding the surface smooth to match the original wall.
The old wall may have a texture to it from multiple coats of paint and the various rollers will leave a stipple like finish. To match this, try watering down topping mud and roll it onto the patch job to blend the old texture with the new patch job.
Measure the hole, or trace the outline of it on a piece of paper. Then, using your saw or utility knife, cut out a piece of replacement drywall that is about 1/8" smaller than your hole on all sides. Measuring twice before you cut will ensure an accurate patch size. The patch piece should fit like a loose puzzle piece inside the hole you've cleaned up.
Jane Tip: Drywall (also known as Sheetrock) usually comes in large 10 foot by 4 foot pieces and considering your hole probably is less than a foot or so wide, when you are shopping, ask for a "patch piece." Most home improvement stores have spare pieces of drywall that they'll give away for free.
Using a putty knife, apply joint compound (also known in the trade as "mud") to the back of the patch, then insert it gently into the hole. Fill in the cracks around the patch and fill in the screw holes as well. Now take a break, do a dance, or catch up on emails while you give the mud time to dry.
If the patch seems a bit flimsy, tape around the border of your patch using a self-adhesive drywall tape and cover it with a thin layer of joint compound.
Jane Tip: Drying time taking too long? Aim a hairdryer at the wall on a low-heat setting to speed it up. Avoid high heat, as it will crack the compound and the surrounding wall.
Once the compound has cured, sand the area so it's flush with the wall. Cover it with a light coat of primer, feathering it at the edges to blend in with the surrounding wall color. Once dry, paint the area using the original paint if possible. Several light layers work better than thick layers here, as you can check the color and texture match as each layer dries. If you find you've laid it on a bit thick, paint-wise, sand it down and prime and paint it again.
If your wall has a texture coating, such as "orange peel", the patch might match color-wise, but unless you replace the texture, it will still be noticeable. You might consider re-texturizing the area prior to adding a coat of paint.
There are three basic types of wall textures: orange peel, sand and skip trowel (also known as "knockdown"). Orange peel and sand wall textures are often available in spray can versions for easy application (see www.spraytex.com). Skip trowel is joint compound that is applied with a trowel by hand in a way that matches the texture of the rest of the wall. Whichever texture you choose, be sure to let it dry thoroughly, sand down any rough or jagged edges, then prime and paint.
Jane Tip: If the hole in your wall was made by a doorknob, install a doorstop in the floor behind the door to avoid future repair jobs.
Once your work is complete and you've cleaned up all traces of your repair, invite a friend or family member to inspect it. Dare them to pinpoint the spot you repaired! While you don't want to make this type of repair every day, isn't it great to know you can handle at least one of life's unexpected mistakes with this much ease?