1Tim 3:8 "Likewise deacons must be reverent, not double-tongued, not given to much wine, not greedy for money"
The role of "deacon" is slightly different than that of "overseer" in that I take it that deacons oversee the material or practical affairs of the church, while overseers oversee the spiritual affairs. An example of a deacon would be in Acts 6 where "there arose a complaint against the Hebrews by the Hellenists, because their widows were neglected in the daily distribution. Then the twelve summoned the multitude of the disciples and said, 'It is not desirable that we should leave the word of God and serve tables. Therefore, brethren, seek out from among you seven men of good reputation, full of the Holy Spirit and wisdom, whom we may appoint over this business; but we will give ourselves continually to prayer and to the ministry of the word.'" Acts 6:l-4
Though I'm not completely certain if that is the distinction between bishops and deacons, seeing as the Greek word "deacon" is used many times in the New Testament and most commonly translated "minister", and its usage is often not limited to practical matters, such as in Colossians 1:23-25 where Paul speaks of himself as a minister of the gospel.
Not surprisingly there is not a lot difference between the qualifications for that of deacon as for overseer - both heavily dependent upon one's character.
To be reverent actually is referring to being revered or honored for one's deeds and character, much as it is written of Timothy when Paul first met him, "He was well spoken of by the brethren who were at Lystra and Iconium." Acts 16:2 and for thus Paul chose him to go with him.
To be double-tongued is saying one thing with one person another with another (with the intent to deceive) And thus a deacon should be sincere. This is somewhat challenging when it comes to positions of institutional authority - where there's pressure to be politically correctness or otherwise a crowd-pleaser.
Again Paul mentions of the issues of drunkenness and greediness, just as he said in verse 3.