Wrapping JS file in function, and assigning that function to a variable
From a organizing perspective you are doing fine, in essence you used the Module Pattern. I would just advise you to consider placing 'use strict'; in the beginning of your function.

As you probably figured out, $ does not collide with jQuery. Though, for this piece of code I would not create a one line function if you are only going to call that function once.

For the email thing, I think it might fool a number of scrapers, I'd keep it.

For fizzbuzz, while your code is working, I think the goal is to use a minimum amount of modulo statements, your code could be written with fewer modulo statements..

My counter suggestion is very close to your code:

// codereview.js:
var codeReview = (function() {

    // "public" functions
    return {
        fizzbuzz: function() {
            var output, i;
            for (i = 1; i &lt;= 100; i++) {
                output = '';
                if (i % 3 == 0) {
                    output = 'Fizz';
                }
                if (i % 5 == 0) {
                  output += 'Buzz';
                }
                output = output || i;
                console.log(output);
            }
        },
        email: function() {
            var first = 'test@em';
            var last = 'ail.com';
            var email = first + last;
            return document.getElementById('my_email').innerHTML = email;
        }
    }
})();

codeReview.fizzbuzz();


This was an interesting read, which provided an alternative inner loop which is more code review friendly:

            for (i = 1; i &lt;= 100; i++) {
                if (i % 15 == 0) {
                    output = 'FizzBuzz';
                }
                else if (i % 3 == 0) {
                    output = 'Fizz';
                }
                else if (i % 5 == 0) {
                  output += 'Buzz';
                }
                else{
                  output = i;
                }
                console.log(output);
            }