The first to consider is purpose.
What I will do with this site?
Don't worry; your home zone might have already determine that for you. Check with your township what can you do at your site before having big plans. If you don't have a zone assigned; you might have to choose one zone type anyway before building. And think well before doing it. Once you have a zone; it's very difficult to change it if even possible.
Your zone can be for private homes, multiple family homes, agriculture, business, homestead.
If you have an HOA in place; check with them first.
Layout everything
Create a layout or map with the natural resources and inclinations of the site.
Include:
How far and high it's to main roads, rivers or dregs, cardinal points.
This information is important to place buildings and their orientation as well as to plan for pumps, water acquisition, and roads. The high of the terrain is good to plan the leveling for each building and whether you need hills or climbers.
If there are dregs or ponds; it's easier to have an idea of how deep your well might have to be. Even though deep wells give you more water; you do not want to make your hole too deep into the soil. You do not want your water to come from an aquaphor (deep waters). The reason is because you do not want to dry out your land permanently.
The aquaphor is to feed it; not to dry it up. It should be used only in extreme cases with the permission of your town.
Maps
The map must follow a scale system. It should be as accurate as possible.
You might want to take a look at the maps already available for your land if any. If you have the money; go to the professionals. It can pay off later on. If not; do your best with what you have.
You will need to measure the leveling of your entire area in order to create an accurate map. Once you have a decent map of the terrain; you will need to make a map of individual constructs including plumbing and electricity. This should include internal roads, reference to the main outside road and easements related the property.
Once you have all the individual maps, recreate your map positioning your new construction with the exact location and submit it for approval.
Secure the money or the loan to start your construction.
Loans
If you are taking a construction loan. There are different types of construction loans. One type is agriculture granted by the SDA only for agriculture purposes, or for rural areas. They could also grant a loan to first time owners.
However; must loans are regular loans where the grantee(you) will have to get a second loan for a mortgage once the construction is done.
Unless you have no choice, hire a contractor or builder. The builder could take care of the permits and the approval and creation of maps and diagrams as well as the purchase of materials.
Permits
Get the permits. Keep the permit or permits present at the site in case of inspectors. Do not start the process if you don't have the money.