Favorite thing: Yes, go to Zanzibar, that's a good idea. Zanzibar (also called Unguja locally) has rainy seasons between March and May, and October and December, and potential visitors are sometimes concerned about this. I was there in March-April, and that's why there were such strange dark clouds and interesting colors (see the opening photo of my page). Still, it was fine going there, and it may only be a shower or two during afternoons that go for rainy season. But it may rain hard over short periods of time..
Yes, go to Zanzibar, that's a good idea. Zanzibar is a popular place, so there are some good guidebooks readily available. If you buy the Lonely Planet one called "Tanzania, Zanzibar & Pemba" you also cover a transit opportunity,Tanzania. Bradt's "Guide to Zanzibar" is more comprehensive and detailed, but tells nothing about Tanzania.
Buy guidebooks beforehand or in Zanzibar/Tanzania.
Favorite thing: wandering the streets of Stone Town as i often did i came across this chinese restaurant that was drying its noodles out in the sun. Too funny for me to not take a picture of. If anyone is interested it was somewhere near mr mitu's place, but don't ask me where as i got lost that day.
Bicycles and motorbikes can be rented to tour the island.
Island roads are not in very good shape, especially in the northern parts. Make sure you have a good map of the area and you are aware of the weather before you start on your roadtrip. Rains can make some roads totally unnavigable.
I also want to note that we were stopped at numerous police checks on our way to/from Airport - Nungwi. Our driver commented that this was normal. The police checked the driver's permit to operate a tourist van and then we were on our way. Make sure you are authorized to use the roads you are planning to drive.
Favorite thing: There are no ATMS anywhere on the entire island. The only one we found was at the airport (arrival lounge), where you can charge a certain amount to your credit card for a commission of 6%, to get some tanzanian shillings. So stock up on cash or tc's before you get to zanzibar.
Favorite thing: Its an island, you cant really get yourself lost, but its fun trying. Hire a motorbike and just ride and ride and see where you end up. In Stone town, just walk and walk and see where you end up, its all part of the fun of being in Zanzibar. Best to spend a day or two in Stone town to view the architecture, the old crumbling buildings, but also make sure you get out to the beaches. Nungwi in the north is where we stayed, but Kiwengwia on the east was probably the most beautiful beacj ive seen in the world(when the tides in that is, its not so nice apparently when its out).
HOUSE OF WONDERS
Also called Beit-el-Ajaib. This wonderful four-storey wooden building is a magnificient example of local architecture. Built in 1883, it was once the Residence of the Sultan. Now is a museum.
At Mizingani Road, by the Fort, in front of Jamituri Gardens, facing the sea.
THE OLD STONE TOWN
The old city of Zanzibar is called the Old Stone Town. It has several monuments and churches, but its main attractive are the hundreds of narrow streets where you always get lost (want it or not) to enjoy the local life and admire the wonderful wooden doors. Though it might seem dangerous to wwander around by night, it isn't at all!!
Another beautiful white sands beach, smaller then Kiwengwa, but with amazing turquoise waters. There are little huts just by the beach to feel yourself in paradise. To get there, head north (there is only one road so far) till the road ends, at the very very north of the island.
At the east coast of the island this looooong white sand beach is great to walk but if you wanna swim, the coral reef makes a pool that makes bathing a bit uncomfortable, as you have to enter quite far into the sea to be deep enough to swim. To get there, rent a car, as there are no public transports.
THE BOAT TO ZANZIBAR
There are several boats to Zanzibar and Pemba from Dar. The normal boats/Ferry take 2 hours and a half and cost 15 US$. The Hidrofoils take 1 hour and cost 30US$. For both you have to pay 5$ of taxes. For tickets, take a walk down Sokoine Drive and you'll find lots of Ticket Offices.
The arrival to Zanzibar is quite magical, as you see the white city with all the dhows going up and down.
You can reach Zanzibar by Dhow (those wooden boats with white sails) too, is much more romantic but it will cost you a lot in money and time (more than 8 hours).