When I was learning rails, I often wish I had a comprehensive checklist of things to learn. I like order and structure when I learn, but many resources lack this somewhat in this realm. That being said, here is a path that I would recommend a new user to follow as they journey down this rabbit hole.
Note: These steps worked for me, on Mac OSX 10.6+. For best results, please replicate.
1a) Pre-work: Sign up for accounts at github, heroku, and stackoverflow. These are all essential. Github is where you can save your code in the cloud and it also acts as an online code resume. Heroku hosts your code on a live website (For free). Stackoverflow is for questions when you run into problems. Extra credit: sign up for any Ruby forums you can find, these will be helpful if you get stuck in the future.
1b) Learn the Command line. I wrote an earlier blog post detailing some resources here. DO NOT SKIP THIS STEP. The command line is easy once you get the hang of it. Follow my post and its resources carefully and you will be in good shape.
2) Installing Rails/Ruby. This can often be the hardest part for people. Try Chapter 1 of this book, and try google/stackoverflow if you run into any issues. Just be patient, this can take time (a month for me to get it right!). Pay close attention to what the command line is telling you as you install each piece.
3) Codecademy. Take one day to go through the HTML/CSS track, then another day for Jquery, then a week to go through Javascript. After that, try the Ruby track, and then come back here to this checklist.
4) You are now ready to build a simple Ruby on Rails app. Try this one: its beautiful, carefully explained, and easy to follow. It’s also a very useful app, especially for a beginner.
5) Here is perhaps the second hardest part of this checklist. Building a twitter-like application from scratch. You already did chapter one of this book in Step 2! So feel free to start at Chapter 2. Here is the source code. Try to hand-code as much as you can but refer to this source code if you get stuck. Most of your problems will be typos! Post to Stackoverflow #railstutorial for great answers. Taking your time and building this app will make your attention to detail stronger, and you will also be introduced to many great concepts in Rails.
5) Here is your next project–a software as a service app. From here, you can build an app that you could actually start charging people money for, which is nice.
6) From here, you’re almost graduated. The final exam is to find a cool gem, and implement it in an app of your own creation. I might recommend Gmaps4rails, or ActiveAdmin. Extra Credit: Build your own gem, and get it published online.
7) Post grad- learn some more about test-driven-development.
Final notes: If you spend a few hours per day at this, you could conceivably get all these steps done in about two months. If it’s taking longer, don’t fret, patience is a virtue. Go to a local meetup or try to make some friends in the online community. Help others who are struggling in the steps you’ve already completed (this will also reinforce your own learning!). The official rails documentation is also a good read.