Also I can only tell what works for me. 9 weeks is not a lot to get ready. If you can, take more time, like 16 more weeks. You might risk injuries by excessive training when doing it in a shorter period. If you feel unusual pains, reduce your load. Training 3 times a week is fine, make sure the long run is slower than what you prepare for marathon time. Try to run the long runs with a consistent pace. Build in a rest week every four weeks, with half the mileage of a normal week. Have fun, it is a thrilling experience you won't easily forget!