Newborn photo advice for a parent

Once you get the lens, do some practice shots in the morning and evening and increase the ISO (with a fairly wide aperture ie 4, 5.6) see you have sufficient light without a flash. A tripod will also help to slow the speed - presuming your baby doesn't move around much.

This might help:

http://www.cambridgeincolour.com/tutorials/camera-exposure.htm