Your professional opinions kindly requested

Ah, summer. You drift by like a hazy dream, wherein keeping the internet world up to date with my craft and occasionally non-craft related activities seems like an insurmountable task. I want to throw out an 'I'm still here', Joaquin Phoenix style (though my facial hair isn't nearly as impressive).

This is where I'd usually commence in bitching, probably in ALL CAPS, about how [insert string of expletives here] hot it was due to the freak heat wave striking the heartland of the US. Ironically, I was dreading a work trip to Knoxville, TN this week--their summers are miserably hot and humid--but at temps in the high 80s, it was practically winter coat weather compared to WI. I don't want to gloat, so I'll just say I enjoyed staying in a hotel next to the 1982 World's Fair Sunsphere:

Knoxville's local wigshop warehouse. It's in much better shape than The Simpsons led me to believe.

And I've been steadily working on my cotton sweater, though dog knows when I'll get to wear it. I'm just about done with the body; there's been no shaping, so if I stopped right now it would be a (very loose) tube top.

It's laid out on a bench at the airport: not really sure why it looks like it's a floating ghostly apparition.  Maybe it's tired of being a sweater and is trying to go into the light.

But onto a pressing matter: two of my cousins have recently gotten themselves knocked up. Buns in the respective ovens. Riding the baby train. Their lives are over (JOKING...one of them already has a child so her life was over a while ago). But seriously, they are both lovely ladies expanding their families and I want to mark the occasion with some hand knitting. We're not super close due to the the long distance we live apart--so I'm not thinking a huge project, but I think that a couple of babe hats would be a nice gesture.

Here's the rub: I know absolutely nothing about human spawn. I might as well be another species. Until a few years ago, none of my extended family was of the right age range to have young children--the first time I held a baby was maybe three years ago (I did the thing where you awkwardly hold it straight-armed out in front of you, natch). So I'm all ears for advice...they're both due in the fall, so the wee ones will be 2-4 months-ish during the wintertime. What size are babies heads at that age? Are knitting patterns for babies sized by age? Any suggestions for patterns that you've liked?