User Guide The Let’s Encrypt project
The word is out about Let’s Encrypt, the free and open-source SSL/TLS certificate authority managed by the non-profit Internet Security Research Group (ISRG). Let’s Encrypt has just dropped their prices to $0.00! This means that everyone can protect themselves without paying anything upfront ever again. And with no cost associated whatsoever, you might ask yourself, why wouldn’t I want to use it? There are so many ways in which this product will make your life better: lower risk of phishing attacks on your domain name; increase in search engine ranking; protection form malicious software like ransomware.
You can find updated documentation here