A lot goes into choosing the right door for a project: style, proportion, joinery, hardware, and more. This illustrated guide by Andy Rae will help. It covers frame-and-panel doors, the type most often used in furniture. Some of the design considerations, however, also apply to slab-style plank doors and veneered doors. Rae advises those choosing an overall frame-and-panel door design to choose carefully: Begin by choosing the style -- overlay, rabbeted, or flush. Then use with good proportions, choose the appropriate joinery, and design it to accommodate wood movement. This guide also covers mounting options, hardware, and techniques for installing glass doors.

From Fine Woodworking #204

Correction:  On page 41, the drawing of a frame being rabbeted along its inside edge implies that the router is moving in a counter clockwise direction, which would be a climb cut. The safer way to make this cut would be in the other direction, as shown here.