Sidebar not working properly

HI!

I am trying to add one page. And on that page i want a sidebar. I do not want the sidebar to come up on any other page. However, when i add the sidebar to that page it only links to the pages i have on that sidebar.

I want the sidebar to be at the left, and having maybe 5-6 navigations to that sidebar.
Once you press some of the navigations the info about that shows up without it changing new window. And once you press something else in that sidebar the new info shows up without opening in new window..

So all info loads on the same page, just switching content when choosing..

Hard to explain a thing so easy that many websites is using, hopefully somebody understands my concern.

Best
Eijkol