Well this is essentially a note to self and well to others too.
The best help documents online for Ruby On Rails and Ruby are these AJAXified websites which allows real-time searching of sytanx and commands.
For Ruby On Rails, it is:
www.railsbrain.com
And for Ruby, we have:
www.rubybrain.com
And the best part is you can even download them so that you can use it offline!
Another good resource for Rails documentaion and help guides is the newly created collaborative effort Rails Guide project. This was started by @lifo as a project to give the rails community a good documentaion which was painfully lacking till now. Since its a collaborative effort, you can participate here. There is even buzz about this project on @twitter
The Hitchhiker's Guide to Ruby On Rails Galaxy 