Don't get it, it will just frustrate you and make you angry unless you don't care about lag and all the other stuff wrong with this game, then camp, camp & camp until you get the hang of it so you don't start off to bad.

Try to make some freinds, that will help and give you some advise, Good People are out there, but sometimes stay quiet, because of all the smart mouth people ....... and a good nerve pill too keep ya calm, until ya get a feel for it

Welcome to the game

Spec ops is a good place to get the layout of the maps and kill confirmed is a good mode to get used to the lanes of traffic and hotspots

Don't get it, it's an awful, awful game.

If you want to have smooth multiplayer gameplay, throttle your Internet whenever you play, or sign up for the worst Internet plan you can. I won't give up my Internet for this piece of ****, but if you want to play smooth online, you need to do that. **** lag compensation!

Welcome Blackstar

First and foremost - Always remember that it's just a game. Play for the fun of it. If you aren't in it for fun; above everything else (especially in the beginning), you'll just find yourself getting frustrated, and rage quitting. Forget about your kill/death ratio, your wins and loses, and all the other stats and just enjoy the game. Naturally, you're gonna get your ass handed to you a helluva lot at first, so watch the kill cams; learn from both your mistakes, and your opponents' skills.

Next, don't get locked into just one weapon. When you're starting out, that's easy to do. Try 'em all - primarys and secondarys. What works well on one map/game type, may not work well in another

Again, welcome.

Keep your powder dry,

Wolf

DONT OPEN IT AND GET YOUR MONEY BACK

Don't bother getting it yet. The game is still completely broken. I would hold off for another month to see if they actually figure out how to patch it. I wouldn't bother waiting for Blops 2 either as that will likely be completely broken when it comes out. They never fixed the first Blops so I have some pretty major doubts that the lag will be fixed when the new one comes out.

MW2 was the last working COD and even that has it's issues because Activision made them rush and whore out their game. That is why the majority of the staff took off to Respawn. 

Every CoD has a good side and a bad side. I own Call of Duty 4: Modern Warfare, Call of Duty: World at War, Call of Duty: Modern Warfare 2, Call of Duty: Black Ops, Call of Duty: Modern Warfare 3, and I preordered Call of Duty: Black Ops 2. If you liked CoD 4, or MW2 then MW3 will be no problem. If you were more into Black Ops then just wait for Black Ops 2 or get World at War. If you have not played any CoD previously get MW3 but please be aware that CoD MW3 is still a work in progress and they are constantly trying to fix the issues. I try not to get to angry about the lag issues that started for me after the mose recent patch because I myself develop games and have my own online shooter. Now IW is different than me, I fixed the connectivity issues first whilst they are seeming to put it last on their list because they want to get the maps and other money making things out of the way. I think once all that has been taken care of connectivity will no longer be an issue.

My Advice

1 - Buy BO, MW2 or even COD4

2 - If you must buy MW3, get it used (should be easy to find considering the amount of people selling the game

3 - Play how you want

4 - Use whatever gun you want

5 - Do not listen to people who use "12 year old" logic (which summarizes 3 and 4)

6 - Play as best as you can, and remember that even if you get massacred it may not be you because the connections/matchmaking in MW3 are not very good (back to point 1)

7- remember, BO2 is around the corner

8 - You do not have to listen to me either. MW3 can be fun (hell most of us still play it even with the constant frustration)

If you MUST buy this POS, then play how you want.  RLBL gives some great tips for you. 

Just note, that with the current match making and lag comp system they have in place, you might be on the bad side of lag.  I can have some great games at times, but then from out of no where my gun starts shooting marshmallows and I can't kill anybody.  it is very inconsistent. 

My personal favorite weapons are AK47, ACR, MP7, P90 and UMP45.  Setup different classes for different scenarios and don't be afraid to change classes mid-game.  You need to constantly adjust your play style to better the enemy.  If you get killed running a certain path, flank around the complete opposite direction next time.  Do not run mindlessly to the same spot over and over again. 

DON'T CAMP!!!.  You will not get better by sitting in a corner waiting for a kill.  I camped when I first started playing COD and realized how boring and stupid it was.  Learn to play the game properly.  You're gonna get destroyed at first and it'll probably take you a COD or 2 (even other FPS or 3PS games will help a little) to get good but it'll be worth it in the long run.  It's  a lot more fun....

Of you can lol@ yourself for dying uncontrollably, you will be fine. Half my deaths are simply out of my control. I'm a decent player, have always only played TDM (on all games), and have a horrible kill/death ratio. it dropped in BO and is dismal on this game. Not that I care, but it is a reflection of gameplay quality.

The lagg is BAD, But if you can live with it, you're good. Every once on a while you get an awesome match. That will keep you hooked until your next one. Lol. I get them about once per week.

Also....people have been compensating for lagg by camping. Watch for people laying prone in walkways.

Save your money, try and buy a secondhand copy or rent the game first. As it is a frustrating game as it runs so bad and you may not like it. And imo there are better games coming up for release soon.

I must say it is quite amusing to read all of the replies in this post. It's amazing how many people thing this game is a broken pile of crap.