Hello everyone,
If you are a newbie to RubyMine it is quite essential that you can feel a little bit lost in tons of its features. RubyMine ships built-in help to help you. Just go to Help | Help topic
Here you can take a short trip in all the features of RubyMine.
One can ask: and what about feature X? Of course it has search capabilities – just select the tab with magnifier on it and here it is.
In the following screenshot I’ve decided to look for Rails console functionality:

Also we provide RubyMine’s help on web, just visit http://www.jetbrains.com/ruby/webhelp
To boost your productivity with RubyMine we recommend you to take a look at Help | Tip of the Day and Help | Productivity Guide sections.
-JetBrains RubyMine team


The Index tab is also very useful, especially if you’re looking for how to use this or that keyboard shortcut, or something like that. Just open it and start typing whatever you’re looking for, then press Enter and it will jump to a closest definition.
Try also the Procedures index. On the Procedures page, click a letter with which the desired action starts (for example, “N” for “Navigate”, or “Z” for “Zoom…”). RubyMine help will show you the list of all procedures starting with this letter – now click the desired procedure in the list, and view its description in a popup, or jump to its page in help.