wait... WHAT????????????? Are you serious????? CONGRATULATIONS!!!!!!!!

It's been neat watching this relationship progress! I remember you writing about your first date with him!

How to prepare... you know yourself better than I do in terms of what you're picky about. I'd start the observation process now, since you have a few months. For me, it would be:

1) does he pay his bills on time, or does he slip often and get stuck with fines and late fees?
2) does he keep his kitchen as clean as you'd like it to be? If not, you should prepare for that not to change once you're together
3) How does he handle crises? Is he graceful and calm (if the apartment floods, or you had a break-in) or is it going to be the kind of situation where you need to take charge? Doesn't to hurt to make sure that your own expectations are realistic.
4) Financial stuff - I was really bad about that part during my two live-in relationships. We were really laid back and whoever paid, paid (and in my current relationship, that person is always me). If I were to do it again, I'd start off by splitting everything either 50/50 or proportionately according to earning potential (notice I said 'potential' - we should all live up to our potential). You can always merge finances later very easily, but once merged and patterns have developed, it's almost impossible to split it out again if the situation seems unfair. I really, really wish I had done that with my husband. Because I didn't, my consequence is that I feel extremely taken for granted. Even if you don't work, Rayna, for both of your sakes, come up with some kind of contribution that you both agree upon for how you will carry your own weight - take on extra household responsibilities or something. This is by far the biggest issue in my marriage, and it's my own fault for not being clear up-front when we first moved in together.

That's it - my best advice. GOOD LUCK! I'm happy for you!!!