I'm a anime fan. I also like yuri anime, and there seems to be a lack of guidance both for yuri series and the... relative level of quality involved. There ARE a few guides out there, including Okazu, the yuri guide over on shoujoai dot com, and P. Kristen's Lesbian' Guide to Anime, but they aren't easily searchible.
My idea is to list series alphabetically by Japanese & English names, rate it from one to five on yuri content (one is subtext, five is full on canon) as well as a review. It should be noted that the reviews will be my opinion, not any 'official' comment, and I will welcome discussion on the titles.
Yuripedia, the Anime
Yuri rating: Five. All the characters are GAY GAY GAY GAY. Gayest gay!
Summary: The all yuri academy of yuri-topia, with students who are all gay, and whom romance each other. The series stars Yuri and Himeko, with Utena, Haruhi and Yomiko, all of whom are mysteriously single and available to date.
Review: The best anime ever. Really. A realistic cast that interact in realistic ways, while set in a believable world. Excellent plot and stories. The only down side was the character of Shanejayell, who was annoying hanging around the lesbians.