First off you have to register, if you haven't yet do so Here. If you have already, follow below, I will give a step by step instruction manual for Mac and PC if possible. (Going by memory on the PC so bare with me)

Of course, the obvious thing you have to do after registering, is logging in. To log in, move your mouse over the symbol near the top of the page. You will then see this underneath it.

And then press , and do so by entering with your name and password. After logging in, you will see three new buttons.

Press the button.

Once that button is pressed, a new page will load, and you should see exactly what is posted below.
Once you see this page load, press the button.

Go to page 2 to continue this tutorial.