Step 1
Measure and mark the section where the fence will be installed. Plan to install a cedar post at the beginning and end of the run, or in each corner if you are creating an enclosed area. Divide each lengthwise run of fencing evenly to allow even placement for posts. For example, for a 24-foot run of fencing, plan to install four cedar posts 8 feet apart: one at each end and two in between the ends, all 8 feet apart.
Step 2
Place the first cedar post onto the sawhorse. Have a helper hold the post steady. With the chainsaw or handsaw, cut one side of the bottom of the post off, approximately 1 foot at a long angle. Turn the post around, and cut off the another foot from the other side. Your angles do not need to be perfect or exact, as you are merely creating a pointed edge so you can more easily drive the post into the ground. Continue cutting the remaining posts.
Step 3
Place the first post into position on the ground. While a helper holds the post, lightly pound the post into the ground with the sledgehammer until the post stands up on its own without assistance. Have your helper stand away from the post. Vigorously pound the post approximately 2 feet into the ground. Continue placing and pounding the posts along the fence run.
Step 4
Attach cedar rails or wire fencing along the posts. If using cedar rails, pre-drill the rails to prevent splitting the wood as you nail them to the posts. Have your helper stand next to the post, supporting it and keeping it from shifting as you nail the rails to the posts. If using wire fencing, unroll the fencing and tack the fencing onto the posts with heavy-duty staples and a hammer.