<p>I'm looking for:</p>

<ul>
<li>documentation</li>
<li>blogs</li>
<li>books</li>
<li>ready-to-use pre-configured slice images</li>
<li>services</li>
<li>wrappers</li>
<li>libraries</li>
<li>tutorials</li>
</ul>

<p>...anything that would make it easier to start using EC2 to host a Rails application.</p>

ElasticFox is a must have utility for overseeing your instances
http://developer.amazonwebservices.com/connect/entry.jspa?externalID=609
Capazon is an awesome utility to bring instance management into Capistrano
http://soylentfoo.jnewland.com/articles/2007/03/27/capazon-capistrano-meets-amazon-ec2
(there is a newer version out somewhere)
I like these AMI's (I dig Ubuntu)
http://alestic.com/
If you're using Heroku or EngineYard (the main cloud hosting solutions today - they build on top of Amazon EC2) you can also use git to manage your code and both Heroku and EngineYard have great instructions on how to use integrate git with them:
Heroku:
http://devcenter.heroku.com/articles/git
Engine Yard:
http://docs.engineyard.com/host-your-code-on-github.html