What about documentation? Having a good and up to date documentation on 
- how to setup the development environment
- what is the coding standard that the team follow
- How to build the project
- (maybe) how to install components like db, key value store etc.<p>Of course having a script to setup the environment will help so the new person can start doing something, they might get error but at least they start getting error that they can work on their first few days.