According to the series of articles linked to by @BillCrosby, the names of the officials convicted and sent to prison are Jacquenline Maiden and Kathleen Dreamer. A third, Rosie Grier, was acquitted of all charges. The two convicted were each convicted of one felony count of negligent misconduct and a misdemeanor count of failure of elections employees to perform their duty. They were acquitted of five other charges.
Prosecutors accused Maiden and Dreamer of secretly reviewing preselected ballots before a public recount on Dec. 16, 2004. They worked behind closed doors for three days to pick ballots they knew would not cause discrepancies when checked by hand, prosecutors said.
Special prosecutor Kevin Baxter did not claim the workers' actions affected the outcome of the election - Kerry gained 17 votes and Bush lost six in the county's recount.
According to here, they were both sentenced to 18 months in prison in 2007.
A judge sentenced two Cuyahoga County elections workers Tuesday to 18 months in prison for their roles in a countywide ballot recount after the divisive 2004 presidential election.
According to here, if you want to become an election official, the conditions include that you must not have been convicted of a felony, so I think that means that these two individuals can no longer serve on an election board in Cuyahoga County. I would imagine most other counties would have similar restrictions in place.
The two workers were evidently granted a new trial by a different judge later in 2007, and in November of that year wound up accepting a plea deal that allowed them to serve probation without actually admitting to any wrongdoing. However, I believe that, since their plea to the charges was "No Contest," this may be enough to prevent them from working on the election board again, though I am not a lawyer and it's not really clear that this is true after their 6-month probation sentence was completed.