As far as I know, there is no way to record notes in-game, but there are some things such as the Info Center that allows you keeps notes in TXT files that can show up in-game after logging in.
(
http://www.eq2interface.com/download...nfoCenter.html )
The only downfall is that you can't straight edit it while in-game. You can edit the text files themself anytime, but they won't update in-game until next complete log-out & log in.