However, I want to keep that going and at the same time establish passive income through multiple streams to supplement my retirement.

Instead, use it to supplement your other marketing efforts... in other words, use zillow as a way to reach sellers, but also scrap craigslist for sellers, send direct mail to absentee/high-equity owners, etc.    

I will do some of that but after listening to some BP podcasts and doing some general Googling I feel that I can supplement my income nicely in the flip or rental game.

So maybe this is supplement to that, or in a unheated area, like an addition. 

I've been reading lots of articles and books about multifamily investing and it seems like these will be a great supplement to what I've read. 

In order to supplement my education, I started watching Youtube Videos on Investing topics such as: finances, stocks, precious metals, commodities, Rich Dad Poor Dad, building wealth.

I know this is a very broad description but I wanted to make this initial post to get a reality check, encouragement, hear from others who have done the same and been able to supplement their long term financial health and freedom etc. 

I'm thinking about getting into real estate investing to supplement, and eventually replace income from my job.

Third, does anyone know of supplemental resources that can help me navigate the audio (i.e.: a digital program, or agenda PDF or other kind of document)?

For the most part they are equity investments in high appreciation areas with my salary supplementing monthly operational losses.I am looking to expand my portfolio through additional purchases that cash flow.