I just got L4D, anything I should know?

the only strategy that ever works is dont buy l4d let alone buying it a few days before the second is due to come out

Tips: Don't play on expert until you're good at it; melee a lot; hunting rifle is tricky; you can't use explosives for Akimbo Assassin; you can't outrun the witch.

Dont play Versus before you can EASILY finish a Campaign on at least Normal.

Make sure to always talk, you'll get bored if you just play the game.

when you get covered in boomer vile throw a pipe bomb or get in a corner and keep meleeing

in versus always have friends that think. That don't work, make some. That don't work, prepared to be most eaten, clawed, puked on (survivors) or shot, burned, shot some more, face end of a weapon, oh and shot (infected).

I think I summed that up for versus mode.

Very important:
Continuously check up on your teammates. Always know where your teammates are. If somebody is straggling behind because he has low health, stay with him. Leave him behind and he'll die.

I get pissed whenever I get pounced by a Hunter and the guy just a couple feet in front of me just keeps on walking, totally oblivious to the fact that I'm dying.

I got an important tip for ya-Dont buy a game when the next one is a week away from release date!

Do NOT shoot the witch!!!