Measure the area to be covered. You will want to use as many whole sheets of 4' x 8' plywood as possible, and remember to leave a 1/4" gap around the perimeter of the room and an 1/8" between the rest.
Note: Plywood is best for subfloors because it holds nails and screws more securely. And make sure the fasteners are galvanized to prevent rusting.
Put nails or screws in approximately every 6" around the perimeter and around the boards. When you lay the plywood, leave an 1/8" between the boards for expansion and contraction.
Cut strips with a pair of scissors, and staple them to the subfloor. Connect the terminal wires to the end of each strip.
Cut the plastic corner of the element to expose the braided wire that runs the length of each strip, and slip the mental connector over the braided wire at the heating strip. Insert the flattened terminal wire into the connector so the two wires are touching, and use the special crimping tool to crimp the connector so it's good and tight.
Cut a short piece of self-adhesive sealant tape, fold it in half, peel away the backing and wrap it around the connection. Press out air and it will form a permanent seal. Route all the wires into terminal boards and the transformer, and call an electrician to install an off-and-on switch.
To begin the hardwood flooring installation, find the longest run of the room. Snap a chalk line down for this "starter" row and every other row can be built off of it.
Start by lining up the first board with the run of the existing floor through the hallway into the kitchen. Then line up a board with the stair nose, which is parallel with the old flooring. Draw a line along this board, and measure from the exterior wall to the board. Now transfer this measurement farther down the room. Do this by measuring from the exterior wall the same distance, and make another mark.
Insert a spline or a slip tongue into the groove side of the board and tap it into place -- and nail it using a pin nailer. This will allow you to attach boards in both directions.
Note: The hardest part of installing new hardwood floors is getting that first row installed properly. Once you've done that the rest builds off that starter row to make the job much easier.
Lay a board off both sides of the starter board. Use 2" staples in the nailer, and set the compressor at 60-70 psi. Use the nailer to set the board and drive the staples through the tongue at an angle into the subfloor. You can use a manual nailer, but for a job this size it was best to use the pneumatic nailer.
Note: You rent a pneumatic nailer and compressor for about $70/day.
Make sure the ends of the boards butt up to each other tightly. Don't forget to leave a space when you get to the end of the room. To assure a 1/4" gap, lay the last row of boards next to the second to last board, and mark it a 1/4" shorter than the space between the end of the second to last board and the wall.
Use a compound miter saw to make simple cuts. A new blade will ensure clean cuts.