The people lending you the money will have done numerous deals.  

Do you keep it on your windshield in plain site or locked away in a vault?

You look for good houses, get okayed for loans, pick the best changes to make, plan your money, put your place up for rent in a smart way, take care of the house, list on many sites, borrow again, and use the new cash to buy another house.

There are numerous ways to do it. 

@Mike Farr I have not used any sites like been verified however you can go to the county clerk's website for the county where you are buying the property and search the owner's name and that will pull up a list of any liens that are on the property.

How does this work? I overheard someone talking about it now I'm interested in learning about it. How much do I need to start off?

Some great resources would be here on BP, passive pockets, SEC edgar site (for example you can review Regulation A fund offerings as well as their financial statements to understand how to read audited financials).

Are there any tried and true/ industry standard sites, forums, etc. where those looking to avoid capital gains look for investment properties?  

Also, some municipalities require that the property be your primary residence and that you live on site to manage.

If so you can still use the STR sites like Airbnb/VRBO and just have a 7 night minimum.