Popular Mechanics just posted up a good instructable on joinery basics, lots of photos and step-by-steps…
The best way to hold together a high-end woodworking projects, whether you’re building a timber-frame home, putting together a trestle table or making a step stool, is with a bit of glue and hand cut joints.
It is easier to use mechanical fasteners, like nails and screws, but to add that look of first-class work, with smooth, metal free visible areas, nothing will do the job like a direct joint between parts, bonded with glue. Of course, the type of joint you need depends on a variety of factors, like the nature of the materials, the function of the joint, strength and appearance, available equipment, and your own level of skill. Joinery may be intimidating to the beginner, but, like any other building skill, all it takes is a bit of practice.
Here we dissect the workings of two primary joints, the edge joint and the mortise and tenon. WIth these joints, you can build a wide array of furniture and tackle a number of woodworking projects without having to rely on unsightly (although time-saving) nails and screws.
instructables : Joinery Basics – Link.