-Be prepared to run Hell with your own equipment. If the room is small you don't need a microphone. All you really need is a TV, a VCR, and a DVD. Bring a flashlight and a power strip and a few AV cords too.
-Have an introduction speech for the event. Let the audience know what Hell is and what it's about and what they can expect.
-Give a little intro or setup for each clip. If you show the Sailor Moon clip, you can say "Hey, who remembers Sailor Moon? Okay, who remembers the insanely terrible live-action American Sailor Moon pilot? No? Well, here it is." Or you can be as simple as "And now, here's a dog riding a bicycle." Just as long as you give the crowd a little context.
-Don't be afraid to halt the proceedings to discipline the rowdier elements of the crowd. A little audience participation is fine, but if the rest of the spectators can't hear or see due to their enthusiastic fellow crowd members, it's no fun for anybody.
-Sit down with all your material and work up a playlist. I like to group the clips by subject, but whatever works for you is fine. Print it out with a big font so you can see it in dim light. If you have a chance, run the material past friends and family to see if they think it's funny. Many times a clip I think is hilarious winds up being pretty flat when shown to an audience.
-Be prepared to jettison any amount of your scheduled material because of time constraints or in favor of newer, funnier material. Your playlist is a guide, not a straightjacket, and is subject to change at any time.
-Suggestions or requests are fine, but ultimately your gut feeling should rule the playlist. Maybe one or two loudmouths want you to show Monkey Versus Robot, but you have another clip in mind that will suit the mood better. You're in charge and should act like it. Plus, it just makes it sweeter when you run their request later.
-Your audience is depending on you to entertain them and is willing to sit through just about anything for the payoff of a laugh. Make SURE that the payoff is THERE. It only takes two or three minutes of no laughs for people to start looking at their watch and remembering they have somewhere else to be. DON'T GIVE THEM THOSE THREE MINUTES.
-Make sure the audience knows to let the convention organizers know they enjoyed the show
and that they want to see it back next year.