Rails categories, subcategories, items and comments

I'm making a simple rails program that would help me categorize my items, for example my music and videos开发者_Go百科:

So I would have main category music and in there rock/folk/house and another category videos with subcategories action/drama/comedy

Plus I want to add items with this fields:

id, title, location, some comments on the item.

I'm pretty new to rails, so I ask for the simplest solution or tips on what to read. Thanks.

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A guide to Rails Active records associations is a good a good place to start: http://guides.rubyonrails.org/association_basics.html