Ah wonderful - wing play is great. I played wing all through my high school years and was forced to play halfback once I hit University and the Samoan wingers that were built like fridges took up residence.
It sounds like he's a formidable attacker - as he gets used to the game he could try inserting himself into the backline at different moments. A powerful wing screaming in off his 10's shoulder is a seriously daunting task for a defender.
If you've played before you've probably already told him, but one piece of advice always stuck with me as a winger - "show them the touchline". When he's defending, rather than rush the attacker he can approach them from an angle that presents the touchline side as an 'out' for said attacker. They'll either try and run through him and find out the hard way that's not going to happen; or try and run around him falling right into his trap!
Sorry. I love that sport. Hearing about someone just getting into it gets me so damn excited.