Jason - To measure the Green to Tee distance, simply use a wheel or pace off the distance from the center of the green of one hole to the center of the most frequently used tee of the next hole. At most courses I ask them to tell me which tees are the most frequently used and I also ask what the percentage of cart use is.
If cart use is high, which it almost always is, when doing the measurement, I follow the path a player would use when playing from a cart. Typically that is walking from the center of the green to the parked cart, driving along the cart path to the parking spot at the next tee, then walking to the center of that tee. In many cases when walkers are on a course with riders they will take shortcuts, in these cases I always default to the worst case (following the cart path). However, if the course is primarily a walking course, I follow the walker's path.