Most simple way to set up info-path for emacs is to redefine it with hook like this.
(add-hook 'Info-mode-hook
(lambda ()
(setq Info-directory-list '("/Applications/Emacs-23.2/Emacs.app/Contents/Resources/info/"
"~/Dropbox/emacs/.emacs.23.2.d/info/"))))
And each dir files must be a 'full-fledged' dir-file, e.g. if you have BBDB info file somewhere outside the original info directory, the dir file there must be like this.
^_
File: dir, Node: Top
* Menu:
* BBDB: (bbdb). The Insidious Big Brother Database.
Note that '^_' is a control character, so you have to put it by C-q C-_.