Just found these today.
http://www.davidbowie.jp/eriwilde/ffxi/index.html#
A mixed Japanese-English site. It has an indepth list of basic information like armor, weapons,and items as well as more advanced information about how to achieve Renkei effects. Found it in a thread on these forums.
http://www3.big.or.jp/%7Ewanpaku/FFXI/index.cgi
A japanese site that I found off the eriwilde site. It includes an in-game lunar calendar that can be useful in synthesizing items as well as schedules for ships leaving ports and whether certain guilds are open or closed.
http://babelfish.altavista.com/
A translation site. It does an adequate job of translating Japanese to english (you can get the idea of what's being said). Cool thing is you can type in a url, select the langauge, and its spits out the translated web page. It has issues with formatting. Use it to translate some of the above sites.