I believe Blades of Avernum takes place after 3, or at least that's where the manual says it takes place.

Note, however, that the various modules that people made for this game could take place at any point on the timeline, or even in a whole different universe, or not have any obvious location. It's like Neverwinter Nights (or its sequel) or Unlimited Adventures in that respect.

All right, thanks. :)

Blades of Avernum is not part of the storyline. Blades is actually a community driven version of Avernum, where you can make your own levels/campaigns/stories. There is a website you can visit that has all the campaigns/stories/levels, etc. you can download and play.

http://blades.nethergate.net/

You can of course make your own "Scenarios" as well.

I'd start with the first Avernum, it was one of the best gaming moments of my life! I'd recommend turning on some atmospheric music on low (since it lacks a soundtrack) and just delve into the amazing story! The last time I encountered a game that had this effect on me was when I first played FF3 on SNES (FFVI)