Fire Senshi's Realm
→ Alright, who honestly hasn't been to this site? If you haven't, I am very suprised. This is one of the longest-running, most comprehensive Sailor Mars shrines that I have ever seen. I am quite jealous of Naomi's lovely page (not in a mean way, I am just very impressed by the sheer detail with which she describes Sailor Mars). Visit this site. It is a must-see.

Hikawa Jinja
→ It sports a unique way of exploring the life of Hino Rei through her eyes and the eyes of her friends. It also has a great deal of information on Rei's relationships with the other senshi. All in all, it is a nice site, but seldomly updated.

K's Once Again Untitled Sailormars Shrine
→ Disappointing title aside, this site has a good deal of information about the Rei (manga version) that we all know and love. There are pages devoted to her relationships in the manga, song reviews, her seiyuu and other people involved in developing her character, and some sketches of her original fuku (0_o).

Rei's Temple of Light
→ Here you will find a bunch of information about Rei (anime and manga) and a few paragraphs defending against the sterotypes thrown on her character by those who do not like Sailor Mars.