Gallery modification for wedding photography website

I'm a newbie who just got through installing the gallery 2 successfully on my PC to test out the adequacy for use in a wedding photographer's website. The objective of the site I'm trying to develope for a friend of mine is to create a password-protected album for each of his client so the the client can access the album and just pick out the photos to print so that the photographer is able to recieve the list via email and send the hard copies of the chosen photos by mail. A good example site that seems to include this fuctionality is http://www.amybucher.com/ which I've found from the sample galleries section.

I'm wondering if an extensive knowledge of PHP is required the modify the generic Gallery 2 that I've just installed, to only include the fuctionality I've decribed above. What would be the first step to achieving my goal? Is there a tutorial that I can follow?

Any information would be greatly appreciated.