A Section was 1 mile square and contained 640 acres. It was divided into quarter sections of 160 acres each. These quarter sections were referenced according to their direction on a compass--Northwest (NW), Northeast (NW), Southwest (SW) and Southeast (SE). The quarter section could also be further divided--for example, a half of it would be 80 acres; a quarter of it would be 40 acres.
When Indiana became a state in 1816, its land could be purchased from the federal government. These tracts of land were then subsquently bought and sold between individuals. The purchases from the federal government were made at General Land Offices (GLOs), with the nearest one to Hendricks County being in Crawfordsville. The Bureau of Land Management's website has a searchable database at http://www.glorecords.blm.gov/ which includes the Indiana land sales.
In a description of land, you usually work from right to left, as the description goes from the most specific to the most general. For example, a piece of land might be described as being
"The NE 1/4 of the SE 1/4 of Section 16 in T16N R1E"
Hendricks County's grantee/grantor indexes for 1826 through 1889, and Hendricks County deed books for 1825 through 1886, have been microfilmed.That microfilm is available at the Family History Library, the Indiana State Library and also at the Plainfield library. The County Seat Genealogical Society (now defunct) typed up the grantee/grantor indexes for 1826 through 1853--the Danville library and the Plainfield library have copies of this book, and you can also request a lookup from it in the Lookups section of the Hendricks County GenWeb.
Arphax Publishing's Family Maps series) shows the location of all the parcels that were purchased through the federal government, and then shows the location of those parcels on a modern road map. J.H. Beers & Co. of Chicago published Atlas of Hendricks County, Indiana in 1878, whichn included plat maps of each town and township (see example, showing part of their plat map for Center Township).
The Archives on the Hendricks County Government website includes digital copies of plat maps from the Hendricks County Assessor's office. These plat maps cover various dates from 1880 through 1940, and include a map of each section, as well as a listing of all the owners and the location and assessed value of their land. See examples of a plat map from 1880.
One reason why genealogists like land records (besides the fact that they can help you locate where your ancestor lived and when exactly they moved into the area) is that they are a good source for finding out about female ancestors when they may otherwise not be named in records. For example, if a man was married when he sold his land, his wife also had to sign on the deed, because it meant she was legally giving up her right to what she would otherwise inherit if her husband died (known as "dower").