When new staff comes on board, there are usually default things that need to happen:  assign a phone number, computer, email address setup, etc.  If these aren’t already formulated and communicated to the entire group, they should be.  This allows for everyone to be on the same page as to what each member of the organization should be assigned and what is expected of them.  Also during the discovery period, some people may find they are lacking in basic office necessities that new employees are receiving allowing them a formal way to catch up with everyone else without feeling like begging.  This could be as simple as a stapler or as convoluted as a community profile on the company intranet.  The plus side is if everyone reads over the list, and something is left off, it can be discussed and added before it becomes a problem for the new guy or girl.

One item that appears to be left off quite a lot are introductions.  When people see a new face around the office, it shouldn’t be the first they are hearing about it.  A pre-emptive communique should come out letting the entire staff know the new hire is coming on board even so far as listing the date they will start.

Then once they are on board, they should be escorted around the office to meet everyone face to face and get a lay of the land.  This allows for the incumbents to feel more at ease forcing introductions and for the new hire to meet everyone.  Also included in the introductions should be an informal paragraph about what each person does and possibly how they may interact with each other in business.  Again, this allows for instant passing of institutional knowledge without the hearsay of the grapevine.  

A more formal introduction can be made at the next all staff meeting(you are having those at least quarterly right?).  Hopefully by that time it will seem like they have worked there and integrated quite well, but still make the general staff remember they are new and can use some guidance and get a large group welcome to feel at home.