Here's a really nice Wooden Puzzle Project.

Seven Piece Puzzle. A view of the seven pieces. All but the last piece in place.   Click on the plan to download a larger - color picture.

Detailed Instructions
*********** WARNING***********
Read my page on safety before building this item.

Click here to download complete directions & plans for the project. (pdf file)

This puzzle is based on shapes consisting of 1 inch cube combinations. The final assembled puzzle is a three inch cube.
Precision size is critical. It is best if you cut the pieces every so slightly larger than the 1" cubes to compensate for loss during sanding.
I recommend you do not finish the wood but leave it natural.
If a truly fine project is desired, use a band saw with a good sharp blade and adjust the table and miter angles with a combination square before beginning this project.
However, the puzzle will work well even with sloppy sizing of the pieces.

Materials needed:
1 good looking 4" x 4" at least 12" long.
>>>> Optional : 1 good looking 2" x 4" at least 16" long.

Construction:
1. First, cut out one 3" x 3" x 1" block for part A.
2. Cut out one 2" x 3" x 1" block for part B.
3. Cut out one 2" x 2" x 3" block for part C if you are using some 2" thick stock.
4. Cut out one 3" x 1" x 1" block and one 2" x 1" x 1" block for part C if you are using only 2" x 4" material..
5. Cut out one 2" x 2" x 2" block for part D if you are using some 2" thick stock.
6. Cut out three 2" x 2" x 1" blocks for part E. Cut one more (for part D) if you are using only 2" x 4" material.
7. Cut out one 1" x 1" x 1" block for part D if you are using only 2" x 4" material.
8. Set up your saw to cut out a piece 1" wide and 1" deep (including the thickness and depth of the blade) with a table miter and/or by clamping guides/stops to the table.
9. Cut the 1" x 1" notches out of parts B, D & E.
10. Change you guides to cut out a piece 1" wide and 2" deep.
11. Cut the 1" x 2" notches out of part A.
12. If you are using some 2" thick stock, carefully cut out part C.
13. If you are using only 2" x 4" material, glue the 1" cube part to the ‘L’ shaped portion of part D.
14. If you are using only 2" x 4" material, glue the 2" x 1" x 1" part to the 3" x 1" x 1" portion of part C.
15. Sand all surface to a smooth finish.
16. Now… here’s the tricky part : assemble the puzzle.
17. Sand the exposed edges to a smooth - flat surface.

Note…the puzzle is not that hard to figure out but if you give up, you can click here to download complete directions. (pdf file)