How to Install Magento Sample Data with Video
Installing sample data in my opinion makes Magento a lot easier to use and understand due to the site being loaded with products and categories that you can edit. I know that when I first installed Magento, I was lost when I looked at my empty store. I couldn't exactly understand how to add categories and products but once I had some to work with, things became easier to understand.
Just keep in mind that if your store has any items now, you will lose everything once you install the sample data.
In addition to that, you will also get locked out of your store since your admin password and username will change once the update is complete. This is mainly why Magento recommends that you install the data prior to installing Magento.
Of course, if you do decide to install the data after installation is complete, you can always change your password, domain and DB configuration by editing files and database tables. I however, didn't do that in the video below. Instead, I just dropped all tables, imported the sample data mysql file, uploaded the sample data files and folders, deleted the local.xml file and then just simply ran the Magento install wizard.
Keep in mind that this process is similar to installing Magento without sample data so if you're not familiar with the process, I recommend reading this article prior to proceeding.
So once you have uploaded Magento, you are ready to go.
Can't view the video? Watch it on YouTube
Now just download the sample data from the Magento site.
Since I downloaded the zipped format, my computer automatically unarchived being that I'm on a Mac. If your file is archived, unarchive it.
Open the sample data folder that you just downloaded and upload the catalog folder from within the media directory. To the media directory on your site.
Import MySQL file
If you already installed Magento, you will need to drop all of the tables in your Magento database prior to importing the sample data MySQL file. If you haven't, just do the import. E.g., open phpMyAdmin, select the MySQL Magento database, click import, in the "File to Import" section, click the upload button and select the file with the .sql extension in your sample data folder.
Additional step for those that already setup their store
Prior to running the install wizard, you will need to delete the local.xml file. This file is located in app > etc.
Run the install wizard
Now just go to http://yourdomain.com/install and complete the installation.