The desktop version of MapPoint comes in two editions: North America and Europe. Although both editions have basic low-res coverage of the world (typically city locations and rough coastlines), they only have the street information and demographic information for their respective areas.
I haven't heard anything from Microsoft suggesting they might produce an African version. If they did expand the range, I think Australia/New Zealand would be first - due to the number of requests.
Street maps are going to be difficult to find - does Ghana have its own national mapping agency? If so, try them.
If you just want an overview map, then you could try the CIA World Fact Book (which is online). This will have a map and statistics. If you're from Ghana, you'll probably find their interpretation of your country amusing too
(the UK has had some funny mistakes in the past - I'm from the UK)
Richard