Basic Directory Authentication

I'm trying to add the last piece, authentication, to my new website
running Rails.

I am converting from from an apache environment where I used .htaccess
for each user's login needs.

From all the books I have on Ruby, I only see one example of

authentication code that uses the acts_as_authenticated plugin but the
explaination seems alot more complex than my skillset.

Is there an easy way in Rails to prompt a user to create a password,
then use the environment variable USERNAME to allow only that user to
access his home directory?

Any help would be greatly appreciated.