Grif, you make such nice quotes for me.

Seriously we'll end up with an oversized party at this rate unless we kill one or two off every couple weeks.

I can help with that whole "killing" thing :3, but can you say "Oh god is that a ♥♥♥♥ bear?" Of course FalconX won't see it coming.

Until he reads the forum posts. If anyone ELSE wants to have gay sex in a dnd campaign I'll toss my dice roll bot into the channel with them.

Well, I started playing pen-and-paper RPGs about two years ago. My first RPG ever was Dungeons and Dragons. Ahhh... Memories... Beheading party members for not respecting ancient dwarven mores was so entertaining...
Beside DnD, I play Call of Cthulhu (the d20 conversion) and a friend of mine is introducing me to GURPS.
I've always been a player, and i'm looking forward to DMing some sessions.
Actually i'm working on a d20 campaign based off the warhammer 40k universe. However it's more focused on investigation and minor fighting rather than full-scale battles, much like Dark Heresy, from what i've heard.

Does anyone have advices?

The campaign setting you are trying to make sounds exactly like Dark Heresy. You are better off getting the DH book and using that. It is rather unique from other tabletop RPGs I have played. GW seems to do a crazy awesome job on it and Fantasy RP.

Mhh, I downloaded a .pdf version and I 'm waiting for the translated edition to be published in my country to order it. It's very interesting... I'll try to work some way to make the characters start as normal citizens rather than already in the Inquisition. The first part of the campaign is all about them getting involved in something and eventually being selected by an inquisitor.
I also gave a look at the Xenology book, it was quite interesting but unfortunately
it's not going to be published here soon.

Having been out of touch for so long, how much of the mechanics does one need to know to play this?
Should I just keep a player's handbook nearby?
Also, is the DRL game being played in 3 or 3.5?

3.5

Is it safe to assume that all player spots are currently filled?

Probably splitting in two.

I am strongly attracted to the idea of running my own game, but I don't think I will have any particularly compelling plot or whatever for you guys to follow at first.

On the other hand, I hope to make it reasonably fun for you guys by having a map that you can use to decide where you want to go and what you want to do there. Depending on the players you might just constantly run around the wilderness killing bandit camps or you might spend more time around cities doing quests and whathaveyou.

But first I have to read the entirety of the main Core books, so I can run things as smoothly as possible.

When my exams finish in 2 weeks, I might join in with this if you guys don't have a massive fuss if I make a mistake.

I'm currently running a game with my friends, so does anyone know of some kind of online, multi-client grid thing for allowing people to view the current state of the map?