I have not acted as a game master for a game in decades, but have been hanging around on Myth-Weavers for a little while, and have begun to get a sense for the speed and functionality of pbp gaming. Since I can't find (or, at least, get into) an Eberron game, and I really would like a chance to explore the arcanotech of artificers, flying ships, lightning rails and the heights of Sharn, I am considering following the site's advice and starting my own campaign.

If I were to do that, which official Wizards reference products (both 3.5 and 4e) would you experienced GMs recommend as worth their price and/or effectively essential to a campaign? Alternatively, which web-based resources would you use instead?

--Undercliffe

Either the Eberron Campaign Setting or Eberron Campaign Guide are both loaded with campaign ideas.
Sharn: City of Towers has enough material to run an entire campaign set in Sharn.

Most of the other books have been great as the occasional reference, or have had an idea or two that have inspired me, but I would definitely get started with those above first. No sense in buying Secrets of Xen'drik if your players are never going to Xen'drik, y'know?

As for web-based resources, you should absolutely check out the Dragonshards Archive. There's tonnes of great stuff there.
And if you have a DDI subscription, there are Eye on Eberron articles that may interest you.

If you're looking for anything in particular, please feel free to ping me and I'll give you some suggestions about where to look.

Thanks very much for your prompt reply; I'll look in those directions.

If you're also just getting into things, I would recommend the MW GUIDES listed in my signature, paying special attention to Vol 3 and 4.