I really like the background!
I don't have an issue navigating at all as the various navigation pages are prominently displayed. Some of the pages, such as home, do seem a little too informative or busy though; however, a return visitor would quickly get used to it and might appreciate it.
My biggest issue is with the way photos are displayed.
1) The thumbs are a little small on the home page as showing on my 17.3in (1600 x 900) screen, given no large photos are displayed automatically.
2) The enlarged picture, after clicking on a homepage thumb, could also be slightly bigger. You should also do away with the title showing over each enlarged picture as it shows with the mouse and as folks already know from having chosen to view a certain group. Otherwise make the title smaller because it pushes the picture down, thus cutting off the bottom. That pushes the "back" and "next" thumbnails completely off the page. You may consider utilizing simple back/next arrow keys or placing the thumbs on either side of enlarged picture, versus bottom. There's plenty of room to the right as it's layed out now.
3) The enlarged pictures in the galleries are much larger than the one's on the homepage. I think they should be the same and somewhere in between the respective sizes.
4) You should do away with the drop down menu under the Gallery. Just have them enter the Gallery as they would the Weddings or Portraits. It does seem a little tacky for "Sports" and "Cars" to be displayed so pominently to the formers.
I like the site other than these few tweaks.