One site that gets regularly updated, as well as regular posts by the authors and primary modmakers is Heroes Community. Heroes Community Forum ERA II (WOG) thread
(Its a little over 80 megs. Be sure to download the update 2.43 as well.. Also, check the last page of that thread; there is an issue with autosave which they explain how to address.) Mods which have been converted to ERA II
This mod is great. A few things are unbalanced, but I just don't use them. For instance, its neat to be able to permanently summon elementals to your ranks, but the AI can't deal with it. But its a very good option to include in hotseat player v. player.
Oh, one thing. Be sure to do a clean install of HoMM before adding WOG. And if you are using WIN7, be sure to install somewhere other than Program Files.