Before traveling, make sure you have the yellow fever, hepatitis A, tetanus and typhoid vaccinations up to date. Malaria prophylaxis is highly recommended - consult a medical doctor for advice on which type to choose.
HIV is prevalent, as are most major sexually transmitted diseases. The CDC in the US listed Guinea-Bissau as a groundswell point for new HIV infections.
Depending on the length and purpose of your stay, also consider vaccinations for typhoid fever, hepatitis B, rabies, meningitis and tuberculosis.
If bitten by a dog, cat, monkey or bat - seek a doctor as fast as possible, no matter if you've been vaccinated or not. Everybody needs post-exposure rabies prophylaxis - but if vaccinated beforehand, you'll need less vaccines. Rabies can be prevented with vaccines and immunoglubulin, but once the symptoms present, there is no cure and about 100% die.
Always use a condom when having sexual relations with new partners.
Make sure you drink only bottled/filtered water.
There are numerous internet cafÃ©s in the center of Bissau, but ask around, more of them are hard to spot from outside. Other options are Lenox or go wireless in Restaurant Phoenicia or hotel Bissau Palace.
There are three mobile companies in Guinea Bissau all with prepaid mobile cards, that can be bought all over. It's easy to call abroad or other mobiles of the same company, but can be hard to call from one company to another e.g. MTN->GuinÃ©tel.
MTN GSM 900 - simcard 500 FCFA, not very expensive to call Europe or other African countries. Will soon be possible to get internet connection via an MTN mobile.
Orange GSM 900/1800
GuinÃ©tel GSM 900
Portuguese is the official language and the language used for writing, however creole is the language spoken among the locals. There are several local languages such as Fula, Balanta, Mandinka, Pepel, Bijago etc. But you will always find people who speak English and French from other African countriesThe Gambia, Senegal, Guinea Conakry, Mauretania, Nigeria. You can buy a Creole/English dictionary at the WEC Mission which is in Caracol, and in the Mavegro supermarket which is located right next to the SimÃ£o Mendes Hospital on the road that passes on the right hand side, 300m forward on the right