To explain to you, a hub is a page exploring a topic in full and can have several mini posts, videos and pictures on it.
This rock guitar hub has information on why you might start playing guitar, picking the right guitar for you. How to get started playing, also there is your riff for beginners which you can progress the difficulty. It has advice on the next steps for your playing and other resource you can use.
To see the hub on Hubpages go here,
Playing Rock Guitar Hub.