What are the rules for deducing interest and taxes on a parcel of land that is brought as an investment with an intent to build and sell multiple housing units on the parcel in the near future?

Davensharma:

The property taxes are deductible as an itemized deduction unless you are subject to the Alternative Minimum Tax (AMT), in which case they are not deductible.

The interest can be deductible (at least partially) as an itemized deduction if your intent is to use one or more or the housing units as either your primary or secondary home. If not, then you can add the interest to the property basis to reduce the capital gains taxes you would pay on the profit when you sell the housing units. The same thing can be done with the property taxes is the AMT is an issue for you.