You're on the right track, I find it hard to brainstorm without any visuals
options = ["asia","europe","africa","america","australia","antarctica"]
Next, let's introduce some randomness
var option = options[Math.floor(Math.random()*options.length)]
There's a lot of material here for you to work with
jQuery("#map-container AREA").click(function () {
jQuery('#map-container img.region').removeClass('selected').css('display', 'none');
jQuery('#practice-container ul').removeClass('selected').css('display', 'none');
var regionMap = '.' + $(this).attr('id') + '-map';
var regionList = '.' + $(this).attr('id') + '-list';
jQuery(regionMap).addClass('selected').css('display', 'inline');
jQuery(regionList).addClass('selected').css('display', 'inline');
});
You should update the click function to trigger on document ready and substitute AREA with the option. If using a hash is more suitable for you then:
document.location.hash = option;
You're making good progress, keep it up.