Here are some useful places to look if you become stuck or are looking for inspiration.
###Rails Guides
Great reference material for beginners with walkthrough examples.
###Rails Docs
The full API reference for the Ruby on Rails. Searchable and exhaustive.
###Ruby Docs
The full API reference for the Ruby language. Searchable and exhaustive.
###Heroku Getting Started Guide
Step by step walkthrough on how to set up for Ruby and Rails deployment on Heroku.
###My Guides
Step by step walkthroughs for topics requested by Steer students.
###Try Ruby
Friendly interactive guide to Ruby syntax.
###Acts as Commentable https://github.com/jackdempsey/acts_as_commentable Add easy comments to your models, great for blogs, etc.
###Acts as Paranoid https://github.com/goncalossilva/acts_as_paranoid Stop accidental deletions from your site with this. Very useful if your users have abilities to delete things.
###Acts as Taggable on https://github.com/mbleigh/acts-as-taggable-on Want to add tags quickly? Add this to your Gemfile, do two commands from setting it up and you're away
###Acts as Tree https://github.com/amerine/acts_as_tree Sometimes you'll have models where an object will have child objects (e.g. categories with subcategories)
###Chronic https://github.com/mojombo/chronic A natural date parser which can turn strings like "thursday" and "22nd of june at 8am" into real times. Great for calendars.
###Devise https://github.com/plataformatec/devise A flexible authentication system. At Steer, we like to write our own, but Devise can save you a lot of time if you want something quick and easy.
###Geocoder http://www.rubygeocoder.com/ An amazing gem for geocoding, find out exactly in the world things are by their address. Great for mapping software.
###HTTParty https://github.com/jnunemaker/httparty Need to grab data from APIs? Use HTTParty to make it easy. Use it with Nokogiri if dealing with HTML and scraping.
###Kaminari https://github.com/amatsuda/kaminari Need pagination on your site. Kaminari takes 2 minutes to set up. Easy.
###Koala https://github.com/arsduo/koala Want to use the Facebook API? Then Koala will save you a lot of time. No idea why it's called Koala though.
###Nokogiri http://nokogiri.org/ Grabbing HTML from other sites? Deal with it easily using Nokogiri's CSS-style selectors
###Omniauth https://github.com/intridea/omniauth Need to login with Facebook? Twitter? LinkedIn? Foursquare? Omniauth can help you out
###Paperclip https://github.com/thoughtbot/paperclip Need to attach images or files to your models? Paperclip will do handle it for you. Use the aws-sdk gem if you want it working with Heroku
###Pusher http://pusher.com Want to add real time events to your site. Pusher.com is a service that lets you do it quickly.
###Roadie https://github.com/Mange/roadie HTML emails are a pain in the arse to make but Roadie lets you do it in the usual way and it does all the hard work for you
###RDiscount https://github.com/davidfstr/rdiscount Want to use Markdown on your site? RDiscount will provide you with ways to convert your text into HTML
###Simple Form https://github.com/plataformatec/simple_form Forms in Rails can be a nightmare to code up on your own. Simple Form does want it says on the tin… makes it easy.
###Split https://github.com/andrew/split An A/B testing tool for checking what converts and doesn't convert on your site. You will need Redis set up for this but it's pretty straightforward
###Stringex https://github.com/rsl/stringex Get sexy URLs using Stringex, a lot nicer than using parameterize in Rails
###Stripe http://www.stripe.com Payments made easy. We use them on the Steer site, it's not the easiest gem to implement, but it's a million times easier than dealing with 99% of other payment gateways
###Twitter gem https://github.com/sferik/twitter Want to use the Twitter API? The Twitter gem is really handy and abstracts away all the complicated crap
###Active Admin http://activeadmin.info/ Get a fully working CMS system without really trying! (Support for this is patchy, great when it works)
The Slides for the Ruby on Rails course at Steer are available as a zipped pdf here.
A cheatsheet for using the Sublime Text ERB snippets plugin. (Thanks to Russell for finding this one)
In browser Git tutorial.
Use SSH to comminicate with services like Github.