EC-Council (https://www.eccouncil.org/)
“The International Council of E-Commerce Consultants (EC-Council) is a member-based organization that certifies individuals in various e-business and information security skills. It is the owner and creator of the world famous Certified Ethical Hacker (CEH), Computer Hacking Forensics Investigator (CHFI) and EC-Council Certified Security Analyst (ECSA)/License Penetration Tester (LPT) certifications and as well as many others certifications that are offered in over 87 countries globally.”
EC-Council certifications have been around for many years and the CEH is probably the most well-known ethical hacking certification in the industry. If you are working in an environment that utilizes the DoD 8570 or DoD 8140 mandates, then looking into EC-Council is definitely worth it to open doors for job opportunities.
CEH (Certified Ethical Hacker)
Books
CBT Nuggets
Cybrary.it
ITPro.tv