Q: how do I put my itunes files in icloud?

That is referring to "iTunes in the Cloud", which is a service that allows you to download certain categories of media purchased from the iTunes and App stores to your devices, as explained here: http://support.apple.com/kb/ht2519.

If you want to store your entire music library in iCloud (up to 25,000 songs), including music not purchased from the iTunes store, you have to subscribe to iTunes Match: https://www.apple.com/itunes/itunes-match/.