Here we go again...
Well, JWH, this came up quite recently but was geared towards freelance writers. I think the answers you're likely to receive go something like this...
Contact info: Companies aren't going to come looking for you. By the same token, they likely won't post any contact info here because they would like you to go to their own website, have a look around, and then contact them using the addy posted there. It's a good idea to have some kind of editing sample to send them as well as to be ready to edit a work for free just to show you care.
Using freelance copyeditors: Not being a game company, I can't speak to this, and it is likely a response might be found here. However, I'd also suggest poking your head into the Monte and Sue Cook's "Writing and Editing Boards"
http://pub79.ezboard.com/bforwritersandeditors90779
Industry standards: Again, I'm not sure this is the kind of thing that will be answered here. Companies will probably hash this out with you if and when YOU contact them.
There is another option for all of the above, though I don't know when it is scheduled for release. Anna Dobritt is working on something called the RPG Freelance Writer and Editor Handbook (or a title similar to this) that lists a great many game publishers, their contact info, needs/wants, etc. much like the "Writer's Market" books.
Hope this helps.
