The quick version is...
Trumps, some miscellaneous graphics, most text, and html formatting by Kate.
Callidora, Illidor, and retouching of other graphics courtesy of Meilin.
As the Shadow Shifts (Except the B5 episode preview) by Cael.
M:tG Amber expansion set description by Mikee.
The breakfast food story and quote-scrying in ATSS by Dave.
The story of Ur-Avalon by Eon.
The Avalon 5 logo by Zanzibar.
Source material for various other stories is mostly from Charles, Eon, and Cael, though the Peanut Gallery [including Mike, Jennfier, Meilin, and Zanzibar] and the early run logs [kept by Susie] also provided input.
For those who like recursivity, here's a list of links back to this page (well, actually the top level page).