Unless you regularly work with Rails, it's inevitable that you'll end up forgetting the various commands aimed at making your life easy. Although Googling your questions is always a good approach to solving problems, I find this cheatsheet (and boilerplate app) to be slightly more helpful.
Basic Command Line
Rails generate is a command line tool that can help you quickly build Models, Controllers, tests, etc for your app.
Here's how you get quickly get an inventory of everything Rails g can do.
Create a Controller and take notice of the pluralization.
rails g controller my_controllers
Update your database schema
Create a task
rails g task my_task action_one action_two
Advanced Command Line
Once you get the hang of using rails g, the next step is to start decorating it with data types, modifiers, etc.
Datatypes help provide context about the Models you are making by describing them as Floating Point Numbers, Strings, Text, Integers, etc. By including a :datatype to your model, Rails will set up the database column to perfectly handle the object.
List of Data Types You Can Use