What do you do as a team leader to make a new joiner feel comfortable?

There is usually something called "INDUCTION training" that is given to new staff members.   Such training gives the necessary ORIENTATION towards the new job, new company and new work environment.

This reduces the amount of work you need to do as team leader towards new team members who join your team to make them feel comfortable. 

Here you need to stress such things as clarity, transparency, fairness , subjectivity, and overall team work , team spirit and team reward !!