There are a lot of good resources (mainly from real estate brokerages).

Thanks for all your insight and resources. 

If the landlord gave you documents (including the estoppel) than you may be able to do something if this what you find when you officially start collecting.  

Technically you can be forced to remit all collected rents to the former owner, because you were never legally entitled to possession.2) They can file suit against you and ask the court to declare the sale void.

Also, if anybody has any good suggestions as to which websites or resources they use to find their market data I would greatly appreciate the feedback.

Even if so, you're almost never allowed to collect double rent. 

It collects from a variety of data sources.

Roofstock Zack: “We are making sure your PM, Marketplace, will receive the security deposit, the tenant info so they can collect rent payments, and the keys if available”.

Wait a minute are you saying that owning rentals is not a passive investment and you can just pitch it to management sit back on your barcolounger and collect mail box money ????

Can you provide some links to resources where I can learn more?