What is the cost of clapboard siding installed?

You'll want to get a few estimates - I suggest at least 3. They should offer you free estimates. Be sure you check out the company via the BBB, and be sure they are bonded and insured. Ask for several recent customers that they have worked for.

For more info, see the following page on wood siding:
http://www.building-your-green-home.com/…

Hope this helps.