Pocket hole joints are really not new and are most often used in furniture construction. For decades, commercial furniture manufacturers have relied on pocket hole joinery for the super-quick and efficient assembly of furniture. This type of joinery has found its way into the homes of DIY wood project builders. That's largely due to the pocket hole jig, which is now available in just about any woodworking supply store.

At first glance, a pocket joint resembles a simple butt joint. It is not a groove, dado, rabbets, or other fancy joinery. It is just two boards stuck Pocket hole joint together end to end. However, a butt joint by itself is a relatively weak woodworking joint, and usually requires some type of hardware or fasteners to make it work. That's where pocket hole joints come in. Using a special jig, builders drive a pocket screw through the edge of one board and into another at a 15 degree angle. This creates a surprisingly strong and durable joint between two project pieces, and in many cases, does not require glue.

In addition to its remarkable strength, the joint also offers the following great benefits

No complicated joinery skills.
No fancy woodworking tools or use of an inexpensive power drill/driver.
No glue required. The joint is strong enough to leave as is without gluing
Joints Completely Hidden. Holes can be easily hidden with plugs to cover the screws.
What you need for pocket hole joinery is:
Kreg Mini Jig (kit)
Drill Bit
Drill/Driver
6" Square-head drive (#2)
Pocket Screws
Wood Clamps

To make the pocket hole joint simply to align the jig on a board (where the screws will be located) and clamp it in place. Most pocket hole jigs include adjustable guides and runners to help you get the jig aligned exactly where it needs to be for a particular size boar.
Drill the pilot hole with the special bit for drilling the pilot holes (an ordinary drill bit won't work). The unique design allows the bit to leave a small "pocket" at the entrance, where the head of the screw will rest after completing the joint. The bit should also feature an adjustable stop collar, which controls the depth of the pilot hole. Be sure to check your instructions to find out how to set this ring to match your board thickness.
After drilling the pilot hole, remove the clamp and jig from the board. Then take a quick look to see if the pocket holes are the right depth, and in the right position. This is also a good time to clean up any rough edges the bit might have left behind.
Because of the self-tapping feature of pocket screws, a pilot hole is only needed in one of the boards that are joining. As a general rule, it's better to drive screws into the side of a board (against the grain), rather into the end of a board (with the grain). This is especially true for self-tapping wood screws (like pocket screws), which have a tendency to split boards if they are driven into the end grain. After you have decided how you want to assemble your project, note where the edges and ends come together and plan your pilot hole locations appropriately.

That is all there is to it.

See related articles:

Biscuit Joinery

Dadoes and Groove Joints

How to Make Dovetail Joints