RSpec and Selenium automation of an application


Hi All,
I am new to rspec and
I am using selenium with Rspec1.2.4, I have gone through describe, and
it methods etc.

I am automating an application which contains many testsuites and test

my question is

  1. Should i write one describe method corresponding to one
    testsuite ??? And one it() method corresponding to one testcase???

  2. If Yes, then how would i execute more than one describe methods one
    by one as same as running testsuites one by one If i want to keep each
    describe() in separate file.