Correct Way to Hook jQuery Script in Wordpress - php

Question

I've got a Wordpress site and have a .js file that I would like linked up so I can call the script. After much research, I've found this must be done with a hook in functions.php. I've tried all sorts of variations but cannot get the official method to work, but I have found a way that does work but just breaks the rest of the site in the process.
What am I doing wrong? I know about the get_stylesheet_directory_uri() & get_template_directory_uri() differences with parent and child themes but neither seem to make any difference.
Here's the 'official' way that doesn't work:
function add_jquery_script() {
wp_enqueue_script(
'my-script', // name your script so that you can attach other scripts and de-register, etc.
get_stylesheet_directory_uri() . 'http://<site>.com/wp-content/themes/dt-the7/custom-scripts.js', // this is the location of your script file
array('jquery') // this array lists the scripts upon which your script depends
);
}
The 'not recommended at all' way that works but breaks the rest of the site:
function add_jquery_script() {
echo '<script type="text/javascript" src="http://<site>/wp-content/themes/dt-the7/custom-scripts.js"></script>' . "\n";
}
add_action('wp_head', 'add_jquery_script');
As always, any help much appreciated. Thanks guys
UPDATE
After echoing out get_stylesheet_directory_uri() I can see that my URL needs to be relative, which should now be as follows, however it still will not work.
function add_jquery_script() {
wp_enqueue_script(
'my-script', // name your script so that you can attach other scripts and de-register, etc.
get_stylesheet_directory_uri() . '/custom-scripts.js', // this is the location of your script file
array('jquery') // this array lists the scripts upon which your script depends
);
}

Answer 1

PHP
You need to call the function add_jquery_script(); before it can be expect to output anything - pretty simple, easily forgotten.
JQuery
The script was breaking your code because of a reference error, var price definition should be moved inside the function so it is in the function's scope.
http://learn.jquery.com/javascript-101/scope/
$(document).ready(function () {
refresh();
$('#bittrex-price').load(bittrexPrice);
});
function refresh() {
var price = "[domain hidden]/realtime/bittrex-realtime.php";
setTimeout(function (price) {
$('#bittrex-price').fadeOut('slow').load(price, params).fadeIn('slow');
$('#bittrex-vol').fadeOut('slow').load(price, params2).fadeIn('fast');
refresh();
}, 1000);
}