Openstreetmap and it's associated tools are quite powerful.
But they won't allow you to add generic text to stuff, unless it's to a closed polygon that's tagged such as: landuse=farm name=Rhubarb's farm
Osmarender won't attach a scale, because it's made to make map tiles, not printed maps.
If you want a scale, it'd be something you'd have to add in after the map is rendered. - Such as by using inkscape / imagemagick / GIMP.
What I'm trying to say is, is that openstreetmap and all of its apps have probably done most of the work for the app you're after. But it has by no means done all of it.
So for the rest you could either modify some source code, or do the rest of it manually if the farm you're wishing to survey isn't too big.
If you have the time, I suggest you have a play around with openstreetmap, and JOSM to get a feel for it all.
Openstreetmaps most common tags can be found here:
It's not a bother at all
Thank you for that advice, I will look into this over the weekend. So I assume I can add text,scales & more.
Hope I'm not bothering you too much, if so tell me.
The easiest way to do this would be to use openstreetmap's tools.
You can walk around a farm with your GPS, and take a gpx log of where you go (you can even take photos of stuff as you walk along).
Load up the gpx file in a java app called JOSM (java -jar josm-latest.jar)
It's probably best to follow the josm wiki to help you learn how to use it.
You don't have to upload the map of the farm to openstreetmap.
Then save your traced in farm to .osm format.
Then to make a nice printable map, you can use a tool such as osmarender, which will give you a nice svg.
Osmarender looks scary at first, but once you know how to make it spit out svgs it's really quite easy.
To calculate the area of an enclosed way (like a cow pasture field), use josm to get the "measurement" plugin.
Of course if you need some more help with this, let me know.