QuoteMySQL server name
You're usually safe in leaving this as localhost, as most MySQL servers run on the same server as the web server.
QuoteMySQL username
This is the username that you created with full rights.
QuoteMYSQL password
This is the password that you gave the user.
QuoteMySQL Database name
Database name. If it doesn't exist, and the user has the ability to create databases, it'll create a database with this name. For sanity's sake, you can call it yse or yabbse, your choice.
QuoteMySQL Database prefix
defaulted to yabbse_, you can name it anything you want, especially if you're not going to share this database with any other script.