The Lytchett 10 mile race - course map
The route leaves the school by the main entrance gates, turns left and does a loop of around a mile and a half before passing the start line again. The second time the course turns right and heads towards Lytchett Matravers. There is a water station that you will pass twice, the first time between 4 and 5 miles, the second time between 7 and 8 miles. As you run back to the school and the finish line, you will pass the main entrance and enter the school from the side entrance.
If you'd like more information you can find the route on MapMyRun: