To avoid the most obvious bloomers...
So - you think you might want a little background information before throwing your 2c in, do you? Well, as a zepper you will already be familiar with our "site of origin" (or something like that), Roger's Galleon's Lap and the Zone Enchanted Place. If you're not: Shame on You.
Once you've refreshed your memory at rogweb, you may still want to do some more reading. An excellent place to start is at James' Pooh Corner site - well researched and informative, it's not only one of the oldest, but also one of the very best sources of information on Milne on the web. But, being a zepper, you naturally already know that...
And, uhm, that's all I can think of right now. You'll find links pages at both of the above, and to some pretty neat sites, too, but not much in the way of stuff that would qualify as background reading. I'll look into it... (Oh, and please mail me if you know of a site you feel would qualify).