Whenever I introduce a new cat to my house (I have done this twice in the past two years) I set them up in the family room - litter box is already there, add food and water bowls. It also has lots of nice hidey hole corners under the end tables. The other cats and dogs all wander in and sniff and look, and the new one can either sniff and greet or hiss and swat. What I have noticed is that at night, when my son and I and the other pets go to bed on the other side of the house, and it is quiet, the new kitty comes out and explores.
These last two cats have been more skittish coming in then I was used to (too many foster homes and sudden changes in their little lives) - so it took them anywhere from a week to 3 weeks to assimilate into the household.
Since they are in the family room, and it is the room that my son and I hang out in, they get lots of time with us, but still have a safe haven while they adjust.
Pets will adjust on their own - just remember to give the new kitty and your existing pets lots of attention. The new one so it comes to know you as its human and the existing ones so they don't get jealous.
Your new kitty will venture out at his own pace. Just be patient.
Oh, and congratulations on your new addition !!!!!