how to debug rubny on rails application on aptana 3 studio

Hi i am using rails 3.0.12 and ruby 1.9 and Aptana studio3, just i
started to learn ruby on rails , i got one sample project from open
source, i want to debug and see the flow of compiling. i am not getting
how to debug rails application line by line and how i see the values
while debugging, any one have idea please help me out.

Thanks in advance

V.Venkat

This is not an Aptana mailing list: http://www.aptana.com/support