Press on it till little x's appear on all of your apps and they start to wobble, click on the x on the one(s) you want to disappear and then press the button on the frame of the iPad (the one just above where you put the charger).
I'm really tight and only get free stuff - if you have any small people about, make sure you log out of the app store as one of my darlings downloaded a game that cost £69.99. I am currently really into hidden object games. (Ps - eldest child has shown me today how to move the app pictures onto different pages, just to keep it all looking tidy.)