Well, I was in your situation not too long ago so I can offer some advice.
Pretty much everyone told me not to do it (which was the right advice) but I did it anyway, so I'll focus on some things to do if you decide to go through with it. Looking back, minus not moving in together in the first place, I would have been sure to do the following prior to making the move:
1. Discuss how utilities will be divided. Who will be responsible for actually making the payment to the utility company, and when will the other need to have their share of the funds to the other person? What will happen if you don't agree on the temperature. If you agree to do 50/50 but then he insists on hiking up the AC to where it's 60 degrees does he have to pay more than 50% for this choice? Think about it? Would you feel it's fair to A. freeze & B. pay more for it.
2. Discuss who will pay the landlord and also when the other person will need to contribute their share by. What are the consequences if that share is not on time?
3. What happens in the fridge/freezer? If you go out and buy your favorite Ben and Jerry's for a special occasion and he eats it before that time comes what happens? Is it clear what you buy is yours and what he buys is his? If someone eats someone elses food what happens? replacement, reimbursement, nothing? Beware of assuming he will be fair and you both will contribute to the fridge/freezer/pantry evenly. If not, you'll see he's eating your groceries, then you'll feel like you can't buy anything cause he'll take advantage of it, and then you'll find yourself with nothing in the fridge, etc.
4. Think of his contribution to the rent as "gravy, or icing on the cake." But don't put your name on a lease you couldn't afford without his contribution. What if he suddenly gets hit by a bus? I know, awful, but you'll still have to pay the entire rent yourself. Add up your income & costs and determine what you can comfortably afford. Then get a place in line with that.
Overall, don't make any assumptions when it comes to financially related matters. It's really hard to call someone out on a behavior that you didn't specifically discuss beforehand. Sample conversation:
How could you eat my icecream??? I bought that for girls night
What do you mean your icecream? It was in our fridge!
But I paid for it!
So, what's in the freezer is common property
No it's not!
Since when??
Etc.
Sorry to sound so cynical, but maybe this will help you steer clear of some issues I experienced personally. If nothing else, it's better to avoid a potential problem that may never actually occur than to assume it won't and then be screwed
