Both Hard and Private money are typically financial instruments used for investment properties in the short term or when all other options have been exhausted.

The lien instrument (deed of trust or mortgage depending on state) will be recorded, and the original promissory note and any other disclosures will be sent to the lender, and once the lien instrument is recorded the lender will also be sent the original.

She was instrumental in helping me negotiate and beat out the competition for a 20% cash-on-cash ROI.

I'm seller financing vacant land and was wondering, when using the deed of trust loan instrument, if the borrower can build on the property as they see fit (obviously adhering to zoning restrictions) even though they don't hold legal title? 

If by contract you mean Loan Documents (Note, Loan Agreement, Security Instrument / Mortgage, etc.)

For example, if you wanted them to just be on the debt side of the equation, then you are talking about a promissory note and a lien instrument like a deed of trust or mortgage being recorded with the city/county. 

Here's some snippets from the HUD handbook on the subject: "A principal residence is a property that will be occupied by the borrower for the majority of the calendar year"And"FHA security instruments require a borrower to establish bona fide occupancy in a home as the borrower’s principal residence within 60 days of signing the security instrument, with continued occupancy for at least one year."

@Augustin Calderon  if you are putting something in a trust that is a legal instrument and you should consult an attorney.

Jacqueline Lembesis- She was instrumental in this projects success.

That way you can match up one individual lender to one property, the lender gets title insurance and is named as a mortgagee on the hazard insurance, and you sign a promissory note and whatever the lien instrument is in your state (mortgage vs deed of trust).