Congratulations on your new born!
We were in the same boat (no pun intended) six years ago, our son was born in April. So we were dealing with a 2-3 month old when we started coming back to the lake regularly. It was an easy transition as newborns sleep alot and I think the motion of the boat set him at ease.
Two of our favorite places were Blueberry Island (north end of lake) adjacent to Black Cat Island, there is a shallow area with a sandy bottom. The other was the south end of Bear Island near Camp Lawrence, the area across from Mark Island is great as it gets the afternoon sun.
We loved the Bear Island area so much we ended up buying a place there.
Hope this helps.
FYI, this year will be easy, wait until he/she can move around!