Lets say you want the left frame to be have the navigation index (that means the links to all the various pages) and the right frame to actually display the page which user clicks on in the left frame. Then have the list of "a href" in left frame and set their target to right frame.

Also, since it seems as a beginner level question I would suggest you to do some readings for javascript. Try out w3schools.com, irt.org or do a search on google for javascript tutorial. (I may be wrong in assuming that you are new to javascript, if that is the case you can ignore this part).