Sorry, should be clearer! Google Cloud Print is a technology that lets you connect your printer to the internet. It's not on every printer that has Wi-Fi, you have to look out for the symbol on the box and Google has a list of those with official support. You hook the printer up to a Google...
If you have another computer you should be able to set the printer up via that with Google Cloud Print, or you can fork out £40 for a new printer that supports Google Cloud Print. But no, you can't just stick in a USB printer and go with Chromebooks unfortunately.