The last time you joined a new operations/devops/sysadmin team, what make it easy or difficult to get started?

For example... if procedures aren't documented, it can be very difficult to know how to perform them. The rest of the team does them by memory, but you are spending your time asking for help, or guessing your way through them. Well-documented procedures (or even tiny bullet lists) make it easy to be self-sufficient quickly.

What have you found made assimilating into a new team difficult? What have you seen teams do that made it easy? What did you wish a team had done to make it easy?

Please answer in the comments.