I have started learning Ruby on Rails about 4 months ago...and found that learning the basics of the Ruby programming language essential in understanding some constructs such as Hashes, Arrays etc. and how they are implemented in Ruby.
Although the following tutorial is very basic...I think it is quite a nice introduction to programming Ruby.
Also, I found this tutorial quite useful in understanding advanced concepts of Ruby...
As for a tutorial that demonstrates how to install Ruby on Rails and create a very simple application, I find the following tutorial to be very useful and introduces the concept of Model View Controller.
If you are interested in getting a video tutorial for Ruby on Rails. I recommend the following from Lynda. It covers all aspects of programming in Rails, including security, authentications, etc.