Valid passports and visas are required for all foreign nationals visiting or living in Ghana. If you think you might travel outside of Ghana once you are here, you should request a multiple-entry visa at the time of application, rather than a single entry visa. It is a time-consuming and confusing process to get one after you've arrived. For stays of longer than a few months duration, you will likely need to visit the Ghana Immigration Service to obtain a Residence Permit.
If you are living in Ghana or visiting for more than 90 cumulative days in a year, you will also need to register for a Non-Citizen Ghana card. The Non-Citizen Ghana card was introduced in early 2013, as part of the National Identification Authority to manage the identification of foreigners in the country. All foreign nationals are required to register (with some exemptions) and this includes all children over the age of 6 years. For registration and further details, visit the Foreigner Identification Management System website at www.fims.org.gh. (Note: As at May 2013, this was just being introduced).
According to tenets of the Vienna Convention on Road Traffic, if you hold a valid driver's license issued from your home country, you are permitted by international law to drive in Ghana, provided that the driver's license if written in English. If your driver's license is issued in a foreign language (i.e. French, Spanish, etc.), you must obtain an International Driver's Permit (IDP), which basically affirms, in several foreign languages, that you hold a valid driver's license from your home country. You must carry your IDP along with your home-issued driver's license at all times. That being said, it is relatively easy to obtain a Ghanaian driver's license provided that you posses a valid one back home (see Transportation section).