Carpentry and Woodworking - Moving bookshelf

I have a void behind my office wall approximately 5' in width and 8' in length. I am interested in building a bookshelf that will slide and have an opening in the sheet rock behind the shelves. I thought this would be a neat area for my kids if I finish the area as a hide out. I am interested in any ideas how to make this work. hinges? tracks? My office is carppeted and in a finished area therefore I would ant it to look as inconspicuous as possible. thanks!

What you seek has been done for hundreds of years. The old bookcase hiding the secret passageway trick. A bookcase will have a lot of weight, so needs hardware that will support that weight. You need a specialy manufacturer/supplier. Grainger comes to mind, but I can't think of something specific.