We can arrange to meet you at the airport, and go with you to Jambiani, just let us know.
From Zanzibar to Jambiani, it is more comfortable to take a taxi, which costs about 45 dollars.
You can spend a night in Stonetown and get a minibus the day after, it's about 5 $. Mini busses run usually in early morning.
If you go by your self to Jambiani, ask for Dudde and Jambiani Guesthouse at Coco Beach hotel, we are almost neighbours.