I'd use ArcGIS or Map3D but you're better off with Google Earth and making a kml file. An Arc license is $1K I think, not to mention it's also kind of a piece of crap. Grass GIS is free but it's hell to setup and learn.
It also depends on the level of detail you want. There will be some GPS drift in your tracks if you just walk the trails but it's generally good enough. Just be wary of tree canopy cover because GPS signals will bounce like hell and you'll get super inaccurate tracks when you go to import to kml. I've heard forestry guys just clear cutting swathes of trees in order to get a good GPS signal for surveying a forested area so yeah....
Also iPhones, at least for Geocaching are accurate enough with it's GPS that it can be almost as good as a purpose built Garmin unit.
If you want it to be able to be viewed by people on their iphones you might consider doing an ArcGIS online thing but it's a pretty steep learning curve if you have no previous experience in the basic GIS stuff (otherwise it's as easy as pointing and clicking).
ಠ_ಠLess QQ more Pew Pew
READY TO >> RACE