Demographics in the area is 95%+ Caucasian and most of the working class is blue-collar.  

Specifically I want to start circle prospecting, FSBO and FRBO prospecting, and looking for target demographics for cold calls and mail campaigns. 

If it helps,  I have found that on average 1 in 40 properties has unpaid tax bill within 3 months of the tax bill due date.I also provide email append, phone append, and demographic append services for the collected data, and if available by the county deed/mortgage information.  

Then I look at things like unemployment rate, age demographics etc. the us census is a good place for this as is google.

Older long term residents will leave and migrate elsewhere due to unpalatable changes, whether political, demographic or COLA, and new residents will move in who desire that lifestyle.

My demographic tends to be a set of grandparents with their adult children and grandchildren, so I am planning on having space to cater for the grandparents and parents downstairs & kids upstairs.  

What demographics you are looking for in a market will largely be determined by what type of investing you are looking to do, and what "success" looks like to you.

Trulia: use for demographics (% college grads, owner occupy vs. renters, etc), then click on "See businesses, schools, crimes near this home"Zillow:  for rough estimates of rents and value (rents more accurate when you search zillow for similar homes in the same neighborhood)Citydata.com : it breaks down each neighborhood and gives you income, demographics, ethnic breakdown, etc (You already listed that... so not sure what they are getting from it that you're wanting but can't find..)A host of people suggest, Rentometer, Rentjungle, and Rentrange for coming up with the most accurate rental prices.... some people like them, some don't.Calling 3 to 5 PM companies in an area and asking them a bunch of questions regarding the market, how quickly things are going, prices, etc...

We only bring them in when the test ad pulls well and the competing house prices are high, which results in a higher demographic buyer. 

There are some beautiful homes hidden back there that would appeal to that demographic.