jQuery(function() {
	jQuery("#form_field").validate({
		rules: {
			bus_ent_id: "required", //only one method doesn't need brackets
			inv_in_transit: {required:true,number:true}, //multiple methods requires brackets
			outstanding_credits: {required:true,number:true},
			cores_on_hand: {required:true,number:true},
			warranty_part_on_hand: {required:true,number:true},
			comments: {maxlength:500},
			submitted_by: "required"	
		},
		messages: {
			bus_ent_id: "You must choose your store from the drop down list.",
			inv_in_transit: "You must enter a valid Quantity Inventory in Transit amount. If none, please enter 0",
			outstanding_credits: "You must enter a valid Outstanding Credit amount. If none, please enter 0",
			cores_on_hand: "You must enter a valid Core on Hand amount. If none, please enter 0",
			warranty_part_on_hand: "You must enter a valid Warranty Part on Hand amount. If none, please enter 0",
			comments: "Must be under 500 characters in length",
			submitted_by: "This form is not complete. Submitted by is Empty! Please enter your name."
		}
	});
});

jQuery(function() {
	jQuery("#form_field").validate({
		rules: {
			bus_ent_id: "required", //only one method doesn't need brackets
			inv_in_transit: {required:true,number:true}, //multiple methods requires brackets
			outstanding_credits: {required:true,number:true},
			cores_on_hand: {required:true,number:true},
			warranty_part_on_hand: {required:true,number:true},
			comments: maxlength:500,
			submitted_by: "required"	
		},
		messages: {
			bus_ent_id: "You must choose your store from the drop down list.",
			inv_in_transit: "You must enter a valid Quantity Inventory in Transit amount. If none, please enter 0",
			outstanding_credits: "You must enter a valid Outstanding Credit amount. If none, please enter 0",
			cores_on_hand: "You must enter a valid Core on Hand amount. If none, please enter 0",
			warranty_part_on_hand: "You must enter a valid Warranty Part on Hand amount. If none, please enter 0",
			comments: "Must be under 500 characters in length",
			submitted_by: "This form is not complete. Submitted by is Empty! Please enter your name."
		}
	});
});

http://rocketsquared.com/wiki/Plugins/Validation#List_of_built-in_Validation_methods

jQuery Validate Plugin Formatting

jQuery