Hercules World Order - Excellent episode guides and a lot of screen caps.
SF-Fandom - Has a HTLJ message board as well as a Xena one and several other boards to pass your time on.
Caroline's Hercules Page - Pretty good site dealing with all three shows.
Muse's Realm - The updated version of Caroline's Hercules page. It has a few things the old one doesn't and vice-versa.
Hercules IMDB page
Simply Sorbo - a site dedicated to the man himself.
D-Chan's Hercules and Stargate SG1 site - A site dedicated to both shows
The Temple of Amon - Has a Hercules and Xena caption section along with all sorts of other stuff
Australian Xena Information Page - Probably the most comprehensive Xena site on the net.
Xenaville - Another very good Xena site
Mike's Xena Wallpapers - Very big selection of wallpapers - mostly from Xena, but a few Hercules ones.
Xena Community - Fun Xena Message Board and has an attached website
Sherry's UK Xena Page -Features episode guides and a few reviews.
The Warrior's Hut -Down at the moment, but a very good Xena site.
Brian's Xena Wallpaper -Does what it says on the tin plus has Baldur's Gate portraits of Xena characters to download.