This is not a computer made of plywood, but a computer made with plywood. Sorry for the low quailty pictures.

Step 1: Parts and Tools

Parts:
A small piece of 1/4" plywood (roughly 2'x2.5')
Motherboard
RAM
CD/DVD drive
Harddrive
Power Supply
Video Card (if supported by motherboard)
Self-drilling/tapping screws
Floppy drive (optional)
Required IDE cables
Pwr and Reset Switches
Pwr and HDD LEDs
Internal speaker
Sound card (if not on motherboard)
USB card (optional)
Modem/Ethernet Card
Processor (if not on motherboard)
Fan (optional)

Tools:
Screwdriver
Glue

Step 2: Attach Motherboard and Cards

For the mother board, the best way to place it is to have the longest edge of it on the longest edge of your plywood. When you are happy use three or four screws to hold it in place. Then attach the RAM and any cards to it along with the processor if it wasn't already attahced.

Step 3: Power!

For best placement of the power supply, I suggest putting it behind the motherboard. Then tack it down with some glue.

Step 4: HDD and CD

The CD drive can be placed anywhere you want it on the plywood. For entertainment purposes, I took the cover off of mine. This can also be held down with glue. The HDD can also be placed anywhere. I just left the harddrive free so I can use it on other computers I get that don't have harddrives.

Step 5: Lights, Switches, Internal Sound and Floppy

The lights and switches can be mounted or just left free. the speaker can be the same way. The floppy dirve, if desired, can be mounted, with glue, in any space left on the board. The pins where the lights and switches go should be labled on the motherboard next to the pins

Step 6: Fire It Up!

Connect any and all required power and IDE cables. Depending on your HDD,new or used, you might have to install an OS on it. If not you have an interesting and functional converstaion piece. I did not put a floppy drive on this computer because I have no floppys for it. I am hoping to soon have a video of me building this computer on Youtube. I did make this instructable after I made the computer, and actually used the computer to post this.