In the very least, your land contract should include the address of the property and a full legal description of the land. It should also include the down payment amount, purchase price, the number of payments that will be made, the monthly payment amounts, and any balloon payments that may be required. You may also consider creating and attaching an amortization schedule.
I might add that in some development-friendly communities, the city and developer might try to play the eminent domain (condemnation) card. Ostensibly, eminent domain should be used only in the exercise of public good such as a new highway or road widening, though some cities get away with it in dubious circumstances. Your agent should know whether this could be an issue. Such a scenario, as unlikely as it is, would probably force you to hire a lawyer to get a decent price.
Another benefit of subdividing for homeowners who would like to liquidate some of their real estate without having to sell the farm (literally), is that they may be able to both cash in on a portion of vacant land and stay put on the rest. Holding onto some of their land can give that property time to increase in value as the surrounding subdivided land becomes developed.
Pricing land can be trickier when compared to pricing a home. Developed lots in communities may have a clear “market” price based on the recent sale of similar lots. Raw land, however, may have fewer “comparable” sales to use in determining your price. In addition, the price you ultimately can attract for a singular lot or undeveloped land can vary greatly depending on the buyer’s intended use of the property. For example, if a buyer feels that your acreage is appropriate for a high-end home development it likely will bring a higher price per acre than if a buyer only intends to build a single home on it.