Books: A few of my favorite books on buy and hold investing.
The Millionaire Real Estate Investor – Gary Keller
Landlording on Autopilot – Mike Butler
Buy and Hold Forever – David Schumacher, PH.D
Hold – How to Find, Buy, and Rent Houses for Wealth – Chader, Doty, and McKissack

Websites:
www.biggerpockets.com
http://www.adacountyassessor.org/propsys/
http://www.intermountainmls.com/

Podcasts: Podcasts are such a GREAT way to get educated while on the run!
The Bigger Pockets Podcast
The Best Real Estate Investing Advice Ever, with Joe Fairless
(I am not recommending the above because I have been a guest…I literally listen to every episode to keep learning about real estate every single day)
Smart Passive Income with Pat Flynn
The Eventual Millionaire with Jaime Tardy
Freedom Fast Lane with Ryan Moran
Simple Wholesaling with Brett Snodgrass