Administer node??

Hello. Sorry if someone has talked about it.

But, is it posible to add permission for administer nodes? It would be useful because I have a website with a wiki style, and the control of the revisions is a pain. So, I'd like to grant "administer node" to the authors of a book.

I've probed 6.x-1.0-rc8 and 6.x-2.0-alpha7 versions. Besides, I haven't seen anywhere how to add grants with the api. I've seen it's in hook_book_access_author_grants_alter function, but, how is the grant called? Sorry, I'm starting developing modules and sometimes I'm lost.

Thank you in advance!