The biggest part of team building is communication. Employees have their inner circles and cliques. Regardless if you know of these circumstances or not, some employees will not help if someone they don't like is in charge of a team. Like anything, communication plays a vital role in team building and project managing. If you have four qualified people on a team, and they each despise each-other or just don't communicate, they will fail!
The best way to offset any communication problem is to do the following:
1. Define your expectations.
2. Have each team member write out their goals for the project, the company, and their team. Then have him or her sign the document for their file. This leads to more accountability and less bickering or slacking off.
3. Be involved. Don't hand a project off to a team leader without checking in. For example, keep your office door open and insist "brain-storm" session take place at the office right outside your door. Or, have daily update meetings in your office with the entire team. The update meeting can be as quick as 15 minutes - but it will keep people in-check and help the team gel together- and the project come together!