Henry, Henry, Henry... take the baby to the beach. They love it. Sunscreen is wonderful. I was born before sunscreen and some of the earliest pix of me are me splashing in the shallow waves at Jacksonville Beach. This must be your first baby, so don't let it stop your life, bring it along for the fun. Yeah, it's a pain hauling all the baby's crap (literally and figuratively) but it's worth it. You can snap a ton of memories, but you have to get the baby out of the house. (Oh, and don't forget to occasionally leave it with a sitter and get out for fun without).
That Nikkor lens will be great for baby portraits and scenics (not all need to be super-wide). Don't forget to spend some effort to get some good shots of the wifey while she's young and gorgeous.
Once you've passed the entry level, investing in the best lenses that you can afford will pay off both immediately and in the long run. Bodies will come and go, but you'll be using those lenses for many years, if they're good.
I don't know about Aperture's capabilities, but maybe someone on the forum can tell us if it'll do automatic geometric corrections and how to set that up, if it exists. Most of us can live with the distortions so long as we're not shooting buildings at real wide angles. Also, unless you want to get shot, be careful about closing in close on the wife with a super-wide. Stay at the long end for flattering portraits.