I don't invest in MF, but do have a couple of rental properties out-of-state. Here are some of the initial important steps I took:
1.) Research the preferred location (state/city, etc.) - People select their areas for a variety of reasons. What was important for me is a booming economy and an attractive area that I wouldn't mind visiting a few times a year. Also, I selected an area that my husband travels to quite often so he could check on our properties when he flies up for work. Some folks choose locations where they may have family/friends in so they have trusted individuals who can check on their properties if need be.
2.) See the area firsthand - After performing my research and narrowing down my preferred area, my husband and I actually flew out to the city and just played tourist for a few days. This enabled us to get firsthand experience and insight into the area.
3.) Build a team - Once I had my location selected, I began to build a team of professionals (i.e. realtor, mortgage broker; and later - property mgr., insurance agent, etc.). I performed extensive research and interviewed several professionals before deciding on my team. I can't stress enough how critical this step is to investing out-of-state.