This is off topic but relevant for many, if not all of us, as we are integrating into or managing new teams. As a consultant, this is very common.
New teams generally form and evolve through a distinct set of stages; Forming, Storming, Norming, and Performing. The goal is to move to the Performing stage as quickly as possible. I'm currently tasked with managing a very diverse team that is not accustomed to working together. As a result, I'm spending a lot of time working to help them move along the path to high performance as quickly as possible.
Mind Tools has a good article posted that describes these stages with some tips on how to lead a team through them effectively to high performance. If you find yourself struggling to integrate with a new team or building a high performance team of your own you might find this useful.