Many people are having problems setting up their store's categories with Magento. That aspect of Magento is quite simple though and the documentation is pretty clear on that particular subject.

When you setup categories in Magento and they don't show up on your site's front end, most likely your categories aren't setup properly in the admin.

Here is what you should look for:

1. Set the appropriate root category.

This is done in the following way: go to System > Manage Stores and click on your store (not website and not store view – you must click on the store which will show up in the middle column). Then under "Root Category" there is a drop down with all the root categories you have set up – select the correct one.

2. Magento store categories must be sub categories under root category.

All top level categories must be created as sub categories under the root category. Then you can also create sub categories under your top level categories, and sub sub categories, etc.

3. Delete Magento cache and reindex all data!

Most issues will be resolved once you reindex Magento data and refresh all Magento cache. To reindex Magento data follow these quick steps:

  1. Go to System>Index Management
  2. Click on "select all" in the upper left corner
  3. Under "Action" select "Reindex Data" and click submit
To refresh Magento cache, follow these quick steps: Magento Cache Management

4. Lastly I highly recommend manually deleting all files under var/cache and var/sessions.

And remember to delete your browser's cache and cookies to make sure you are viewing the up to date version of your Magento site!