Wow. I moved here from out of state, and I feel SO frustrated with the lack of info on parking, maps of the trail, amenities, and trail conditions in Texas available on the 'net or at the parks. I am used to posted signage which gives you a visual of the trail and periodic "you are here" information along the path. This trail is no exception. Google Maps couldn't even get me there without several searches the closer I got to the trail, and there is NO signage anywhere in Waxahachie to help visitors find the trail. It's as if they're saying (and it's the same with every other Texan trail I've visited so far) "if you're not from here, don't come". Ignore Google Maps directions which take you onto I35E South and to a small parking area at the Waxahachie Depot at mile 1 3/4 .
That said, the best way to access this trail is to Google Getzendaner Memorial Park and begin your ride there. The park has plenty of parking, and there is easy access to water and bathroom facilities. The trail basically starts/ends here for cycling, although you can hike further using dirt hiking paths, and there are also "Health Stations" sited along the first mile or so where walkers can stop and do some fitness activities. At the Wags-A-Hachie Dog Park (about the 2 1/2 mile mark), there's a garden with info about native plants and benches for resting.
Also note there is a dirt "Mountain Bike" only trail (no walkers) which basically parallels the paved path, but forays into the surrounding countryside on occasion before meeting the main path again, and is very well marked. The paved trail has very good granite markers every 1/4 mile so you know how far you've come and how far until the end of the trail by checking out both sides. The trail is 7-3/4 miles according to the marker at Getzendaner Park.
Be prepared that this path winds back and forth, and you can't make any real speed. The scenery is lovely, and the path is mostly shaded with lots of benches situated along the trail. There is water available at the park, and at the Wags-A-Hachie Dog Park (about 2 1/2 miles) and again at the 5 mile mark, where I suddenly lost the trail at an (Unknown named) park. I rode around the park but never found where the path continues for the last 2 1/2 miles, so I turned around.
Also be prepared for horses (!) named LeBron and Shaq who appear out of nowhere, walkers with MP3 players blasting so they don't hear you ask for passing, and a lot of moms pushing strollers. With the path winding the way it does, I had a few close calls with people taking up the whole width of the path, and was almost kicked by LeBron. There was one other cyclist on the Saturday that I went.
In summary, this is a lovely park to walk, but I wouldn't drive there again to cycle. Except for a Subway on BUS287, I did not see any other places to eat, and unlike small towns back east, no signage to direct you back to the main highways. I literally used up my phone battery just finding the trail and getting back to the main roads because my phone kept losing service. It would be nice for a map of the park to be posted at the beginning so you know where different facilities are, and signage at the mystery park at the 5 mile marker to direct visitors to where the path continues.