Guides
How to generate SSL certificates locally.
Short answers to the searches that usually end in an OpenSSL man page.
Self-signed SSL for localhost HTTPS
Why browsers warn, how SANs work, and how to generate a localhost certificate.
Generate a CSR without sending the key
What a certificate signing request is, and how to create one in the browser.
Make a local CA and sign host certs
Trust one Root CA, then issue host certificates for every internal service.