Password protected page for updates

We are looking to have a user protected page added to an existing website that can be very easily updated for open houses we have for the public to view. The user inputing the data has no HTML experiance, needs to be able to add, delete, and modify open houses realtime. Two things: Need a password (admin) side to add, modify and delete the pages. Remember it's got to be simple. Need the page that actually gets displayed to the public. I need this done fast - The next 24 hours. I need it done on your demo site and then for you to intergrate it into my site. I have linux based servers. Please let me know if you require more definition to make this clear for you to bid on. Thanks again.