I got these numbers from realtor.com because the county assessor does not list these figures online. 

Look for the local Skagit County and Anacortes group here in BP, as I understand they meet regularly. 

Do you have a minimum median income level in the county or a certain poverty rate?

Jacksonville, as in downtown, or suburbs, or any of the four surrounding counties?

You can type in any city or even zipcode and it gives you all kinds of great info, household income, population, housing vacancy, housing stock age, mix of multifamily vs single family ect :https://factfinder.census.gov/faces/nav/jsf/pages/community_facts.xhtmlHUD produces occasional annual reports for most metros:https://www.huduser.gov/portal/ushmc/chma_archive.htmlThe Local County Website or city Municipal websites often have great research as well.Development is important in a growing metro because it shows you where people and business are moving.

What else should I be looking for in my county's public property records?

Find a map (I found a free local county book in my area on a free magazine stand that had a map of the area) and drive each neighborhood to get an idea of the neighbors (mostly homeowners or renters, single family or duplex/triplex/quad) vicinity to amenities like grocer/parks/schools/etc. and if area feels like something your target market would be interested in (to buy or rent).Go to your county's or city's website and see if you can find any planning information to figure out where the development is happening.Lastly, find (or start) a local meetup to network and learn the information you didn't know you needed to know.Tax liens can vary by county.

Know that many Counties are backing the Port of Freeport, and the development of Tx HWY 36A. 

I was curious if the market for such as a place as summit county and or lake county are even approachable for wholesaling.I live in lake county currently and the market just seems to expand over time and get more expensive! 

We have only had to foreclose once on an Seller Financed Note and the process was called out in the Deed of Trust (we are in Texas).If the bank does not have a process, there are usually 3rd party real estate attorneys or firms in every city/county that will execute a foreclosure and eviction (if needed) on your behalf, for a fee of course.Good luck...