Main Character list:
* Vash the Stampede: The $$60,000,000,000 man, or at least wanted dead or alive for that amt!  An incredible gunslinger who's infamous for the mass destruction he's caused where ever he's gone (also nicknamed "The Humanoid Typhoon") -- which we later find is caused in large part by the bandits, bounty hunters and others trying to claim the reward!  He's spunky, easy-going, kind-hearted and chummy (think Kenshin, but less annoying and girlie) but he can dodge bullets and can throw rocks to knock bullets off course, among other amazing stunts.  He has acquired Milly, Meryl and Wolfwood as his companions/ allies.

* Nicholas D. Wolfwood: *heart heart* A travelling priest supposedly out to raise money for an orphanage/church who carries a *HUGE ASS* mysterious giant cross wrapped in fabric (I won't give it away).  He also manages to be nearly as impressive as Vash with a gun, despite saying he's a man of the cloth. He smokes, wears sunglasses, and is just scruffy cute (check out his hairy legs when Deathpowder draws him!!!) According to websites n stuff he speaks "badly accented Kansai Japanese" (not like I could tell).

* Meryl Stryfe:  Sent by Bernadelli Insurance company to try and prevent more disaster by Vash the Stampede, Meryl gets along pretty well with Vash despite getting awfully uptight about any chance for trouble that come their way. She's a little stiff, but cool, and carries around a whooooole bunch of little guns under her cloak.

* Millie Thompson: Meryl's ditzy (in a good way) partner- Millie is pretty simple and easy to get along with, and carries one hell of a big weapon.

* Rem Saverem / Lem: A mysterious woman Vash sometimes thinks about. If I told you more I would spoil things.  (for you slashees... her past existance does not spoil things for pairing Vash with bois ;)

* Knives Millions: a murderer (to tell you more would spoil things)

* Legato Bluesummers: Creepy badass who always seems to be eating, and obviously has some bad past with Vash (very fine)

* The Gung Ho Guns : Knives's gang led by Legato... include (I think) Dominique the Cyclops, EG the Mine, Rai-Dei the Blade, Hoppered the Gantret, Gray the Ninelives, Leonof the Puppetmaster, Caine the Longshot, Zazie the Beast, Midvalley the Hornfreak, Chapel the Evergreen . . .
Kuroneko Kuukan (Black Cat Space): This kitty pops up randomly everywhere!!!

Short synopsis of the story theme:
from: http://trigunner.tripod.com/
A long time ago the city of July was destroyed by one man, Vash the Stampede. Although no one was killed there was a bounty of 60,000,000,000$$ put on the mysterious gunman. Now, Many years Later the Bernadelli Insurance agency has sent Meryl Stryfe and Milly Thompson to find Vash the Stampede, and make sure he doesn't do any damage. When they find him they are surprised at how this goofy peace loving gunslinger has managed to live through so many attacks. However they soon find out that Vash is very good at what he does, helping people survive the numerous bad guys that attack the innocent. While protecting others, Vash seeks Knives, a murderer, so that he can settle the score for the many horrible things Knives has done. However Knives is ready with his gang of killers, the Gung-Ho-Guns and their leader Legato.
 

What are the potential slash couples and why?
Vash x Wolfwood, Wolfwood x Vash - (Vash x Wolfwood is my fave pairing- if you can, check out Deathpowder's many awesome djs with this pairing -- thanks to MDBL who got me hooked) These two banter, chum around, drink together and basically give slash fen mondo ammo to work with.

Knives x Vash, Vash x Knives - I don't want to spoil things, but Vash & Knives are related in a way that appeals to many yaoi fans

Midvalley x  Legato - They *look* like Aoshi & Saitoh somewhat. But aside from that, they hang around each other a bit...

Knives x Legato - I can't explain this further without spoiling things

Legato x Vash - that whole enemy - obsession - lover thing

Urls of good web resources or  Urls of slash stories:
Resources
http://www.akane.org/trigun/
http://www.geocities.com/juuousama/trigun2.html
http://nwmra28135.smarttadsl.com/~prof/trigun/main.htm
http://trigunner.tripod.com/