How do I make an avy and use it for my self? What are the requirments and what ever other pieces of information that I need for that? (I'm not the artist, my friend is)

On the persona page, you'll find a link to the avatar uploader. To use it, you also need to have the avatar feature unlocked (MDShop, Extra features).
For technical matters, you might find [url="http://magicduel.invisionzone.com/topic/9102-avatar-tutorial-for-windows/page__hl__avatar__fromsearch__1"]this[/url], [url="http://magicduel.invisionzone.com/topic/6979-avatar-editing-tutorial-for-photoshop/page__hl__avatar__fromsearch__1"]this[/url] or [url="http://magicduel.invisionzone.com/topic/7521-avatar-tutorial-adobe-fireworks-cs4/page__hl__avatar__fromsearch__1"]this[/url] topic helpful, there are quite a few things you need to look out for from a technical perspective (size, alpha, shading, etc.)

As advice for your artist friend, he shouldn't use colors at all, and you should keep the picture after scanning it, you might be asked to send a high-res scan.
If you friend plays MD himself, it'd be better if he uploaded it with his own account and then sent it to you, to keep track of the actual creator in case there are problems.

Also, artist friend must realise that he would no longer own the rights to the image that is uploaded - another reason why it's better the artist themselves uploads the image.