Let's talk about how experience points are awarded.

The Player's Handbooks states:

... as he or she completes adventures and returns to an established base of operations, the Dungeon Master will award experence points to the character for treasure gained and opponents captured or slain and for solving or overcoming problems through professional means. (Gygax, pg. 106; emphasis mine)

An Adventure, especially in the context of the experience point awards, is a very specific thing in BTB AD&D. It is difficult to nail down a specific definition, though. The Player's Handbook describes three different types of adventures: Dungeon Expeditions, Outdoor Exploration, and Town Adventures. It even mentions,

[that] one can lead directly into another sort altogether. (Gygax, pg. 101)

An anology may serve to illustrate how I like to think this works.

I found this gem in the Preface of the original AD&D Dungeon Master's Guide,

As this book is the exclusive precinct of the DM, you must view any non-DM player possessing it as something less than worthy of honorable death. (Gygax, 8)

lol!

I thought it might be helpful to layout a suggested agreement for treasure splitting. This is a pretty important topic to discuss because OSR¹ AD&D BTB² places a heavy emphasis on treasure acquisition. Treasure awarded according to the Dungeon Master's Guide is a significant source of experience points. On top of that, once treasure has been awarded by the Dungeon Master, it is in the Player's realm to divide the treasure as they see fit; including shares of treasure for Henchman. Without a sufficient treasure split, Henchman, who are already only receiving half-xp for Monster slaying, will quickly fall behind the leveling curve.
¹Old School RPG   ²By the Book

You may notice some changes to the structure and layout of the site. I'm still trying to nail down how this is all going to flow and look, so things may stay in flux for a bit. As I go, though, I'll be careful not to lose any of the information that is here.

I also made some additions to the Campaign Rules Notes.

Finally, I have decided the in-game starting date will be 4 Richfest, 575 CY. If you would like, here is a link to a good Greyhawk calendar. A quick summary of Oerth's calendar follows: