The Ghana News Agency (GNA) is doing a lot of data-centered reporting from a lot of polling places scattered around the country. Their Politics page is here.
Here's a good example of what GNA is reporting:
Peaceful voting so far but not without hitches (GNA)
A thorough analysis of the biometric voter systems' performance is, of course, going to have to wait.
[9:30 EST]
Good background story at Modern Ghana from Accra, the capital: Ghana votes in tightly contested presidentials poll.
While many polling stations opened on time, a number started late due to the delayed delivery of materials, causing frustration among voters and officials. Voter biometric fingerprinting was also being used for the first time.[9:40 EST]
Ghana Web also has a good page: Ghana Elections Updates: Five Presidential Candidates Vote. Scroll down to the bottom for minute-by-minute updates from different places — a woman going into labor and voting with her sister before going to the hospital, politicians voting, technical problems, etc. The earliest updates are at the bottom.