Make sure you walk the Via Dolorosa (Stations of the Cross) as well as take the tour around Temple Mount.  It’s a surreal mixture of cultures from around the world.  If you are going to visit the Western Wall, make sure your attire is appropriate.  For those unfamiliar with the local customs, Dairy Bars are very common and do not serve meat, but rather cheese, breads, salads, vegetables and pizzas.  You can find more 'western' restaurants in West Jerusalem and in the Old City.  We walked around the Old City for hours and loved every minute of it.  Also, remember that everyone there serves in the military.  Don’t be put off by all the young Israelis in fatigues and carrying automatic weapons – it is perfectly safe to visit.