Here are some ideas on dealing with a new team member:
- Officially welcome him to the project team: Have a small meeting and tell everyone on the project team that a new team member will join them. Ensure that everyone on the project team is clear on the new member's role and responsibilities.
- Put him up to speed on the project: Yes it's overhead, but there's nothing you can do about it. You need to spend some time to reduce the overall time spent on the project. Allocate a few hours of one of your team members so that he can answer all the questions that your new team member has about the project.
- Micro-manage for the first few days: Yes micro-management is generally bad and it shouldn't be done, but micro-managing a new team member is essential so as to ensure that he's going in the right direction when he's working on the project. Check his work frequently during the day for the first week (or two), immediately tell him if he's doing something wrong, and answer every question he has about the project.
One of the things that I have noticed about new team members is that they are shy to ask questions, which can create problems on the projects. Make sure you explain to your new team member that he can ask any question at any time, regardless of how stupid he thinks it is, and make sure that your existing team members will answer any question he's asking.