I joined /r/babybumps on reddit. It's technically for expectant mothers, which I wasn't, but it was enlightening as a way to better empathize with my spouse. I could also participate by relating what was happening to my wife to the other women there (with her permission of course).

I also joined up with babycenter.com, which has a newsletter that they will send you each week saying what size the baby is "pea, lemon, etc" and things that you should expect like physical body changes as well as logistics like "this week you'll probably get an ultrasound for the anatomy". Stuff like that.

I tried reading some books, but they all sucked and bored me.

Other that that, I tried to get as many big chores done as possible. I cleaned out the garage and storage, trimmed all the trees outside and all the bushes, got the cars fixed and had their oil changed, bought and built the crib and stroller, the kind of stuff that is tedious and hard to do with a baby strapped to you.

And lastly, I tried to get a lot of good sleep. It'll be hard after the baby comes.

Good luck! It'll change your life but for me all the joy and fun has been worth every moment!