Get data in Forms
You could use the serializeArray for the forms. You just need to parse it in the correct way. An example method is provided below
$.fn.serializeObject = function()
{
    var o = {};
    var a = this.serializeArray();
    $.each(a, function() {
        if (o[this.name] !== undefined) {
            if (!o[this.name].push) {
                o[this.name] = [o[this.name]];
            }
            o[this.name].push(this.value || '');
        } else {
            o[this.name] = this.value || '';
        }
    });
    return o;
};
Example in action: http://jsfiddle.net/sxGtM/3/
Get content in HTML elements
You can get the content of an div or something else by using the document.getElementById method and then the innerHTML property
var MyDiv1 = document.getElementById('DIV1');
var content = MyDiv1.innerHTML;
Post object to server using jQuery
function sendData() {
$.ajax({
    url: '/example',
    type: 'POST',
    contentType: 'application/json',
    data: <Your JSON Object>,
    dataType: 'json'
});
}