An older document but with some good guidelines about managing a team of testers.
Guide your team to align with the project objectives
…However, if testers believe they will be blamed for the quality of the software, they tend to develop a risk-averse approach, adopting a position of quality guardians, becoming rather myopic in their view of the world: They stop taking business drivers into account.
Nurture a collaborative approach with the development team
The essential skills of a tester complement that of a developer. Too often though, particularly in the developer-centric world of IT, the tester is seen as deviant to a developer norm.