The easy one-board birdhouse design from Lowe's and the seven-step birdhouse from Popular Mechanics are two good birdhouse designs. The Lowe's birdhouse is made from a single pine board for easy construction, while the Popular Mechanics design allows you to build two birdhouses from one 8-foot long board.
On a piece of 72-inch long, 5 1/2-inch wine pine, cut the eight necessary pieces using a table saw. This includes two 8-inch pieces for the front and back, two 5 1/4-inch pieces for the sides, a 4-inch bottom, and two 9-inch roof pieces. Cut matching 45-degree angles into the front and back pieces to allow for the roof. Trim one of the roof pieces down to 4 3/4 inches wide before proceeding.
Cut a perch 2 inches long from a dowel rod with a 1/2-inch diameter. Sand all of the pieces smooth with sandpaper, and then drill a 1 1/2-inch hole for the opening and a 1/2-inch hole for the perch. Glue and clamp the back to the sides, let it dry, and then do the same with the bottom and front. Use painter's tape to clamp the roof pieces together after applying glue. When dry, glue the roof to the house, secured with more painter's tape until dry.
Alternatively, make a cedar birdhouse with angled sides using Popular Mechanic's design. Unlike the Lowe's plan, Popular Mechanics uses finishing nails to secure the pieces together and calls for enough wood to make two at a time.