Some good plans for small wooden boats are those for the Apple Pie Pram dinghy, the Mini-Sharpie skiff, and the Huntington Harbor Kayak. All three of these boats are easy to build, and the free plans are available online, along with step-by-step instructions.
The Apple Pie Pram is 7 feet long, and the Mini-Sharpie is just under 8 feet long, so it is possible to cut the bottoms and sides for each of these boats from a 4-by-8 sheet of plywood. The Huntington Harbor Kayak is 12 feet in length. All three of these boat plans are designed for the stitch-and-glue building technique which is ideal for less-experienced boat builders.