My county offers a service on their website known as GIS, or Geographic Information System. It is similar to other mapping tools like Google Maps etc, but offers some very useful and unique features like measuring distances and areas, multiple base maps (past aerial, topographic), viewing property boundaries, and linking to property and tax information. Your county may offer this as well, and you should certainly look for it, just try searching for “<my county> GIS”, or visit your county website and look for info there.
Here, you can see my property in our GIS. It shows the property boundaries and some tools in the upper corner. Obviously property lines are approximate and you should get a professional survey or find markers before building near boundaries. In my case, I found posts from the GIS image that mark both west corners and gave me a good idea of where the east lines would fall. This image appears to be from the spring of 2018 when we were having new siding installed.
Here is some playing with the area measurement tool. I’m on my iPad so the accuracy is limited to my fat thumb (my Crayon isn’t working with it for some reason), but using a mouse is much better. In our system you can measure area, distance, or look up coordinates (latitude and longitude). Great for laying out gardens, buildings, fences, etc.
If you don’t have a local GIS, there is always Google. Along with tending to have slightly newer maps, they cover everywhere. In the photo above, you can see where I put my garden along the edge of the mowed area set by the previous owner, which is not exactly straight (nor are my poor attempts at drawing lines). For a garden no big deal, but for a building you may want to be sure its more aligned. I have printed out images as well and marked then up on paper, sometimes a ruler and pencil is easier than digital.
Hopefully this provides you with some ideas. Your local system may differ in its functionality, but checking a few surrounding counties I found them all to be somewhat similar.