Pick a wood that suits your tastes and existing furniture. Lighter woods often evoke a more modern feel.
Cut your lumber to the specified dimensions. If you're inexperienced cutting long, straight lines, have the lumber yard cut for you before loading up. Most lumber yards offer this service, often for free when you buy your lumber.
Sand all faces of your lumber with rough grit sandpaper, then a second time with fine grit paper.
Apply a coat of wood stain to all surfaces of your lumber. Allow to dry.
Set one small wooden sheet and one large wooden sheet in an L-shape. The edge of the small sheet should abut the inside face of the long sheet. Glue in place using wood glue.
Reinforce the joint of the L with a line of eight evenly spaced nails.
Wipe away any excess glue.
Add the remaining small wood sheet to the free side of the L, forming a U. Glue and reinforce as in steps one and two, then wipe away any excess glue.
Set the remaining large wooden sheet on top of your U-shaped frame, forming the desk's surface. Glue in place with a line of wood glue.
Reinforce using a line of eight evenly spaced nails along each 30-inch edge of the desktop. Reinforce the back with a line of 12 evenly spaced nails. Wipe away excess glue.
Look for and wipe away any excess glue you missed. You can usually chip off dried glue with a thumbnail.
Spread a dab of painter's putty over the top of any visible nails. Wipe away excess putty and allow to dry.
Lightly sand any rough patches of dried painter's putty.
Apply a second coat of stain to all visible surfaces of your desk.