Now that you can easily get ssl certificates and set up a secure website, more server configurations come in play. There are a few interesting site to help you check that everyting is well configured. This goes from DNS settings (which you probably don’t host yourself) to the configuration of your webserver for SSL and server headers. New server headers are being defined to help browsers in securely delivering content to visitors.
DNS settings
This site gives a lot of advise on your DNS configuration and helps out with clear informational messages.
A newer and more readable site for checking for DNS issues is now available on DNS Spy scan which is a nice addition to DNS Spy.
SSL configuration
As mentioned in an earlier post, SSLlabs gives good insight in the quality of your SSL implementation and helps to improve your server settings.
Server headers
Most of this is fairly recent browser technology which requires an update of server configurations. The Server header check is a good resource offering links to explanations on the how and why of things. Another useful resource is the CSP Quick Reference Guide