There are a few things that you should know if you're gonna play I'76, especially versus other players.

1. Lag
2. Cheese
3. The .45 Handgun
4. Booting People

1. Lag: What's lag? When you play over the net, not every player's system is exactly in sync. This is lag. It's a real pain in the ass when trying to shoot someone or ram them or whatever. Your screen may show that your 3 Dr Radar missiles hit whoever, but their system may not have registered the hits, so they don't take the damage you think they should. So DONT SPAZ OUT when this happens. It doesn't mean they're cheating. Here are a few tips to keep lag to a minimum:
Don't have a bunch of other programs running when you're playing. The only other programs you should have running besides your connection and I'76 would be something like Hacker Tracker. And take out the I'76 CD when playing net games.
When you host games, the number of players you allow is a big factor. Unless you have a high speed system, try to keep it limited to less than 8 players. 5 or 6 works pretty well to keep things moving. If you have a slower system, I wouldn't go above 4 if you want the fight to keep moving.

2. Cheese: A bad thing. My defintion of cheese is getting lots of kills without being backed by actual talent. Like linking 4 Clusters and pounding someone. That's not talent, just luck. And it really pisses of people who have talent who get interrupted by cheesers. My guidelines for avoiding having a cheesy car are as follows: no more than 2 cannons pointing each direction, no more than 1 mortar pointing each direction, no more than 3 machine guns pointing each direction, no more than 1 fire launcher pointing each direction.

3. Using the .45 handgun: to kill someone with the .45, first their damage meter has to be red, then you shoot them. 5 hits will kill someone, unless they have cupholders or LAG interferes.

4. Booting People: Ever host a game and some jerk enters and you wanna get rid of them? Boot their ass. To boot first you have to have the patch installed (for regular I'76). You can only boot when you're hosting. Push ctrl s to display the list of players in the game. There should be a number beside each player's name. Find the one you wanna boot and push ctrl plus their number (like ctrl 2). You should be asked to confirm or deny booting them, ctrl y to kick or ctrl n to let them stay. Make sure you push ctrl c to turn chat back on. Now that you know how to boot, don't be a jerk and boot people cause they're better than you, etc.