Creating A Nested Category List

Im creating an online retail store. Im trying to create a Category List. I have been able to make a category list but i need subcategories in a nested tree like structure.

Such as the following:

Mobile Phones

• Apple
• HTC
• Samsung

Laptops

• Sony
• Apple

I have tried for 8 hours now and just keep getting stuck.

Im really stuck.

I tried Ancestry Gem.

How would you go about doing this in detail, even step by step would be great?

There are some tutorials but none that i can find that are directly show what im trying to do.