$(document).ready(function() {
    $('.slideshow').cycle({
		fx:    'fade', //effect
		speed:  300, //speed of each transition
		timeout: 4000, //time between transitions
		pause:  1, //pause on mouseover (select 0 for no and 1 for yes)
		random:  1 //randomizes the slides shown
	});
});

//more available here: http://malsup.com/jquery/cycle/