The first thing you must do when you have signed a contract to buy a property, especially where there are professionals involved in representing the interests of either party, is to lodge a caveat to protect your interest in the property until settlement. A caveat will stop the vendor from selling to someone else or encumbering the property without notice to you.
Land contracts are useful instruments for sellers who are selling a home and contemplating carrying the financing for a buyer. It gives sellers a built-in income and generally a better interest rate than rates offered on money market accounts or certificates of deposit. However, a prudent seller should take steps to protect equity and ensure the buyer can fulfill the terms of the land contract.
Personally, I’ve had good experience with Google Adwords where you can set your ad budget to as little as one dollar per day. (You may be able to set it even lower, but let’s get serious, you DO want to sell this place don’t you? Adwords also coordinates with Google Analytics, which will tell you far more than you need to know about the traffic you’re getting to your pages. Also provided are ways to see how effective the ads you write are proving to be. LandWatch.com is another favorite source of mine which consistently supplies better-quality leads, that is, more serious clients, than Google and others.
If you have plenty of time and are not in a hurry to sell the property, and would like to do very little work I would suggest listing it with a broker. They will be able to create a listing for the property, answer phone call and emails, and handle the closing. The downside of this approach is comes at a price and you typically only get local exposure and most real estate agents who deal with both land and homes will most likely put more effort into selling their homes as the commissions are greater.
You can also look to certain companies and organizations that have a concentration of people that may fall in the above mentioned roles such as investment companies (i.e. Charles Schwab, Fidelity), financial advising companies (i.e. Morgan Stanley, Merrill Lynch). There may be a higher concentration of people who can both afford and want to build their own custom homes or to build income-producing properties. Try linking yourself to financial advisors who may already know of people who have these types of dreams. This isn't a comprehensive answer of all the possibilities but just some thoughts. Good luck!