rgd1101 has a good point.
And actually if you can capture the GPS coordinates every so often (dependent on the location accuracy) it would be fairly straight forward to convert those coordinates into a table that could be used to graph out or plot the completed portions of property.
Excel has gotten pretty powerful and if you are farming large areas the inherent errors would probably not be very significant.
Use Lat. and Long. to find distances. Distances (lines) can be used to calculate areas. Straightforward for regular shaped fields (square, rectangular, some triangles). Other places may be trickier but you could subdivide something not so neat into a square and triangle. And just use a good guesstimate for the really smaller, awkward areas.
Depends on how accurate you want your "progress" assessment to be. Land plats could help establish actual acreage as a crosscheck.
That all said you can also use Google Earth (free) to find distances between points on the earth. Along with Lat. & Long.
Build a spreadsheet and see what you can do.... Or ask family or friends who like to do such things.
[Sidebar: Interestingly enough I have a current challenge to my 11 year old granddaughter to find the distance to an old stump way out in a field across from her house. No tape measures allowed.... I printed a Google Earth photograph for her and hope she will realize that she can determine the scale by measuring their garage and thereafter determine the distance to the stump. I think she will be on to it very soon. Plus I once worked with a civil engineer who had software that would take laser survey bearings and distances and convert them to standard X & Y coordinates from which we would plot the property lines. Long,long time ago and I am sure that it is all much easier now.]