Personally, I think the 17-55 lens is very well-suited for weddings, although in the church you may want more tele length. If you are shooting at the full 10 MP (which you SHOULD be), you can crop out quite nicely if you want to create that zoom on the computer. The fixed f/2.8 aperture is very helpful in available light shots.

From Popular Photography: The most optically capable and physically rugged “normal” range zoom you can buy for a Nikon DLSR, this gun is large, heavy, and unquestionably expensive. If there’s a chance you’ll trade up to a full-frame DSLR or migrate to film, pass on it. For other Nikon DSLR shooters with adequately deep pockets, this sharp, fast, (almost) distortion-free all-purpose lens, with its nigh-perfect zoom spread for people pictures and outdoor photography, will be hard to resist."

http://www.popphoto.com/cameralenses/2257/lens-tes t-nikon-17-55mm-f28g-dx-af-s.html

http://www.naturfotograf.com/lens_zoom_01.html#AFS 17-55G

http://www.kenrockwell.com/nikon/1755.htm

The SB-800 is an extremely versatile flash. It comes with a little booklet showing all kinds of set-ups, so I won't go in to that here.