How involved were you before you knew you were going to be deployed? Could part of it be that you are just not comfortable handling a new baby? Could part of it be you are worried about being away, or perhaps not coming back?
Ask your child's mother to show you how to take care of him. If you don't have experience with babies, it can make you a bit anxious at first, but the more you do, however small, the more confidence you will have with him. You don't have to do anything overly involved....just spend some quiet time holding him in your arms while he sleeps...it's one of the best things you will do....
Have his mother take lots of pictures of you with him and get some of the three of you together. Take some with you when you leave.
The video tape idea is excellent....read stories to him on it for example. You can also video tape yourself now and then while over there and send tapes back. If you know where you will be will have access to the internet, see about getting a webcam. I know of other people in the service who use this to stay connected as well.