Ah.
There's something BETTER you can do.
Get something like the Vista Cx and Garmin's Topo software (another $100). Mark the waypoint in the field, with averaging, WAAS, etc. to maximize accuracy.
Then, upload the waypoint to your computer, draw the property boundary on the computer map starting with the known marked waypoint. Create waypoints for the corners. Download these new waypoints to your GPS and download the topo maps to the GPS as well.
Go back into the field with your GPS, now with a topo map in full color on the screen, and boundaries marked, find the points you downloaded, and mark them with flagging tape, stakes, etc.
If you do it just right, you'll be really close, and the GPS with topo map will help you find your way through the hills.
GPS's are neat!
They do take some commitment to learning the bells and whistles. I recommend a book, too, so you understand how the thing works, especially WRT different types of topo maps, compass declinations, etc.
I have the Stephen Hinch book, and can recommend it. Well worth the $11, to get the most from your $300 GPS and $100 mapping software.
http://www.amazon.com/s/ref=nb_ss_g...ooks&field-keywords=GPS&Go.x=17&Go.y=10&Go=Go