Hooray!  Thanks for the reply Frank.  I've worked out how to hide a page!  In the properties bit where you name the link instead of putting in 'Page 5' or whatever title the page would have had, just put a space.  This way the page is published but it can't be accessed from the other pages!  Hope that helps - I'm probably teaching you all to suck eggs but I'm just really excited that I can do the thing that I wanted to do 

Please, please, please, allow us to have hidden pages.  I could potentially lose income as a result of not being able to hide the page that holds the data that I am asking customers to pay me for... I am sure that internet whizzes out there know of some clever way to get round this but for us novices being able to hide a page is a simple and effective way of keeping information private until it is paid for!  Please help me and all the others who have expressed an opinion on this and allow us to have hidden pages.