*I noticed this got a little long, see last paragraph for summary*

OHwhynot's post got me thinking again about money issues, which suck.
I have no clue how to handle FI's and my money once we get married, or right now. FI doesn't seem to be very interested in discussing this, so when the topic does come up, I want to have a "we should do this and that" speech ready. If any married people or people who have done this before can give advice, that would be awesome!
Situation: Currently, we are living together and have separate checking and saving accounts. I moved into FI's house (now "our" house, but not really in my mind). FI has all the bills in his name, and he pays them. I write him a check each month for a standard amount (kind of like rent). I don't like this situation, but conversations that I start about what to do with our money always just die out. I bring it up, and he just goes "well, one day we will go to the bank and make a shared account" Then nothing happens. I think its because both FI and I have no clue what to do, and also FI seems to be just fine keeping everything separate and me writing a check to him to cover my half of the bills each month (I HATE this).
However, I'm much more "domestic" than he is. If left alone, FI would eat oatmeal 3x a day and never go food shopping. So I do most of the food shopping, and it comes out of my bank account. Also, the house is/was a bachelor pad in MUCH MUCH MUCH need of repair (like the kitchen sink ONLY had the hot water spout working - so I replaced the sink). "We" have been doing repairs, but since I'm not working (teacher) this summer, I've been the one to buy supplies and materials, once again, out of my bank account.
Sorry, I just realized how freaking long this got. Basic question: Does anyone have advice on what "steps" to take to merge our money so that shared expenses are shared, but allow us to have our own bank accounts for our own personal spending (FI really wants this)? How did you start the convo. with your SO? How did it go? Any tips for someone having to talk to a guy who's fine with the way things are? (From past experience, what works best with him is for me to go in with a "we are going to do this" plan. Then he modifies it with his input and we put it in action. But I need to know what "we are going to do" first.) So what works?