Teams of voting agents are a powerful tool for solving complex problems. When forming such teams, there are three fundamental issues that must be addressed: (i) Selecting which agents should form a team; (ii) Aggregating the opinions of the agents; (iii) Assessing the performance of a team. In this thesis we address all these points. Categories and Subject Descriptors I.2.1 [Artificial Intelligence]: Applications and Expert Systems Keywords Teamwork; Collective intelligence; Social choice theory