There are many different solutions when it comes to storing data. This article is to talk about dedicated storage, NOT BACKUP. There are a few different options and your situation will determine what works best for you. The one that that is universal, is the hard drives that you should use. NAS hard drives are made to be on all day, every day. Below are the products recommended form home and business use.

This is the universal drive that you should used. The link is for a 3TB, but they come in different sizes, with different price tags.
This enclosure is made to fit the recommend NAS hard drive. The enclosure can be used to attached to a router with USB or to a desktop or laptop.
Synology NAS devices come in many sizes. They are a great option for storage because they are a mini computer dedicated to storing data. They can be connected directly to your network, they have built in applications that allow you to do additional services such as camera recording, music, video and picture streaming. You can also program them to have redundancy to help protect your data. These are nice for home use, but suggested for business.