We went through a purchase and joint ownership with friends. In the end, we made it work, and it was great financially but it wasn't as clean as we'd hoped. It can be messy on many levels - mortgage, title, taxes, decisions about when to sell, DIY vs hiring someone and how to share work equitably, etc.
Once you get a basic sense of what you want to do, the first step (because it is free) would be to find a bank who will issue a loan for 2 unrelated borrowers. Some banks may not work with you at all. Get pre-aproval so you know how much you can borrow for your investment.
Then talk to a real estate attorney and prepare a co-ownership agreement or partnership agreement. They should be able to talk you through issues of the type of title arrangement you want - survivorship vs joint tenancy, as well as putting in writing your plan around how to deal with disagreements, decision-making, arbitration, etc.
There are also issues of taxes and how you split the mortgage interest deduction, depreciation, and then at time of sale, the capital gains, depreciation recapture, etc. Joint ownership may also make it harder (impossible?) to set up a 1031 exchange when you sell, if that's something you want to do.
