For you to get the value of the Value attribute just use this code:
$("input[type='checkbox']").val();
To set a class or id for it then use this:
$('#check_id').val();
$('.check_class').val();
It's hard to know if it's checked or not as it gives out the same value so to check whether it is checked or not, do:
if ($('#check_id').is(":checked"))
{
// it is checked
}
I hope this helps.