If you are not familiar with ruby scripting, don't bother with the ruby console (actually it's under the Window menu). It is used for entering special scripts there but who does not know what to enter, should practically leave it alone... π
There are "ready to use" ruby scripts (plugins) made by scripters and they add fantastic extra abilities to SU. Normally they are just plain text files with an *.rb extension which you need to download into the Plugins folder of your SU application. They appear in various menu items (although many of them are only in the "Plugins menu". Visit or Ruby Forum somewhere at the bottom-ish of the Board Index to see a bunch of them.