The Neptune Pwani Hotel was an excellent choice, beautiful white beaches. The hotel was very clean and the rooms outstanding. The food was good, we just missed eating some fresh fish on a BBQ! Remember to take some snacks and a few good books with as this is not available at the hotel. The hotel shop only have the very basics like suntan lotion. Try and stay away from the beach boys as they hassle you. Do look out for Zena, a lady selling the nicest sandles on the beach! One can negotiate a price of about 15 USD a pair.
Take some mosquito repellant - there are nice mosquito nets in the rooms.