Database Diagrams, but I find this quite clunky with a bigger DB.
Numerous bits of software out there to do the job for you. I've found myself using the latest build of SchemaSpy actually because its quite easy to read what is generated.. but If you want to give people access to the schema within an org, I've had great success with it - for multiple backends... You will need Java, and you will need the MS JDBC drivers....