Question: > 
> **Possible Duplicate:**  
> 
> [Rails 3 deprecated methods and APIs](https://stackoverflow.com/questions/3648063/rails-3-deprecated-methods-and-apis) 
> 
> 
> 

What resources are out there (free or paid) that help walk you through the process of migrating a Ruby on Rails 2 application to Rails 3? I've seen some blog posts (some of which seem out of date) and an eBook for sale somewhere on the RoR website, but what can you recommend as an accurate and complete explanation of what changed from version 2 to version 3 and what needs to be updated when porting to a Rails 3 environment?

Answer: 
Aside from a [number of RailsCasts](http://railscasts.com/tags/27), on the paid front, BDDCasts has one entitled [Upgrading to Rails 3](http://bddcasts.com/series/urlagg/episodes/upgrading-to-rails-3) for only $5. I can't vouch for the quality of the latter (they have some free episodes too), but Ryan's stuff at RailsCasts is top notch.

[Gregg Pollack's videos](http://rubyonrails.org/screencasts/rails3/) on the official site give a great overview as well.

Peepcode also has a [Rails 3 Upgrade Handbook](http://peepcode.com/products/rails-3-upgrade-handbook-pdf) for purchase.
Watch this <http://railscasts.com/episodes/225-upgrading-to-rails-3-part-1>