Currently, in order to store content on IPFS without actually installing it on your local system / contributing as a node, you would need to have a third party provider host your content for you. These providers are typically referred to as "pinning services".
To put it simply, these pinning services host IPFS nodes that "pin" (save) your content on them and make sure they're always available to rest of the IPFS network.
When Filecoin comes online (ETA is still unknown), you'll be able to interface directly into a storage marketplace to store content on IPFS, but it'll likely be some time before that's an option.
If you're interested in hosting content on IPFS without installing it on your local computer, there's a few tutorials on Medium that show you how to set up your own node on a cloud provider (such as Digital Ocean or AWS).
Does that help?