Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load 
DotNetNuke.Framework.jQuery.RequestRegistration() 
End Sub 

Or just reference your own library

From there it's just knowing jQuery, which you can find information anywhere. One other thing that may or may not be mentioned in the post above is that you may need to assign to another variable to avoid any conflicts.

< script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js" / >

< script type="text/javascript" >
var $j = jQuery.noConflict();
< /script >