You can read the reviews of people who have already been there if you follow this link:
The next link gives you details about the hotel location with pics e.t.c
The thing is that Pointe aux Canonniers is located right next to grand Baie which is the tourist capital of Mauritius where you will have all the facilities needed and all the nightlife as well.
This is a zoomed googlemap snap shot. The site appears perfect for some diving and snorkelling!
July marks the transition from Winter to Summer and it should be a rather dry period without (most likely) any risks of cyclones and anticyclones but I wouldn't bet on it.....
Concerning the stuff you need, don't bring too much clothing! Bring the basic ones and buy the cheap cool ones when you can afford some time shopping at Grand Baie or Port Louis, the capital. You'll surely go back full luggage.....
Enjoy your stay