Everyones strategy is going to differ.
First, I investigate the cities - population, jobs, crime, avg income, avg rent on http://www.city-data.com and http://www.Wikipedia.com. I also go on youtube and lookup people who have moved to that city and see what their insights are. Then I look at what is selling and analyze the deal on paper. I may see if the city planning office has any documents online.
Second, I go to the city visiting the REIAs, real estate meetup groups, landlord groups, city planning office. I also check to see if there are neighborhood tours, or I go on any comprehensive day tour so that I can get a feel of the city. I ask the tour guide a ton of questions. If they do not have this then when I get in a cab going to the REIA or meetup group I ask the driver a ton of questions. If I see a cop I'll talk to them.
Third, find a boots on the ground person who will take photos inside and outside of the property that you are interested in. You get these by recommendations at reias, meetup groups, http://www.wegolook.com, biggerpockets. Some people use freelance photographers, college students, and retired engineers that live in the city to do this for them. Some people partner up with the boots on the ground person to "ensure" that he/she will have their best interest at heart. Its up to you what you feel comfortable with.You may want a realtor or wholesaler again recommended by those above. Realtors are going to want to know what type of return you want so that they can help narrow down the process. Some realtors may photoshop pics so beware.
Fourth, after being ripped off I investigate people before doing business with them. Unfortunately, I was ripped off by Wendy Lovejoy who used to be part of GAREIA. So although I recommend going to them, you can not trust everyone including board members. Http://www.Instantcheckmate.com is not too far off in finding stuff on people than from Lexis. Lexis is just more indepth and expensive. There is also http://www.pacer.gov, REI Blacklist on facebook, ripoffreport, better business bureau, consumer affairs, etc. Check the state licensing board and secretary of state to make sure licenses are legitimate.
Fifth, speak to a local lawyer down there. Again the people that you network with above can recommend someone for you or you can check with the local bar association for a referral. Some attorneys might assist you with doing background checks for a fee. You may consider putting the property in an LLC or trust whichever the atty says is best. FL taxes are cheaper than Jersey so these may serve you better than putting it in your name.
Sixth all of the people above can also recommend contractors to you as well. If you are going to do rehabs make sure you know what the ARV is before you purchase. Always double or triple the estimate the contractors give you. A lot of them like to low brow you so that they can get the job. Make sure the boots on the ground person is there 3 days a week to look at the job giving you video and or pictures on the progress.