In game tips and issues...

Since this covers several game types I'll post it here and maybe someone with the game guide, can add to it. I'm going to put these up here since I know several people will be starting up this weekend. They are not really issues more than things to be aware of when you jump online for some play. These are things that I have run into personally.

1) If you try to invite someone to coop they must be working a lower level than you (That's why I couldn't join Conquerer)
2) A higher level player can invite you into their squad and you can play any game type even though if you try to join a game type alone it is "greyed" out. Thanks Mike and Merc.
3) Death cards can be recovered in both single and coop play, Thanks JP.
4) Last chance holds some responsibility now, if another person has this on and you do, you can go heal them. I see this as 2 guys having this perk and working together as being very hard to stop. This is also used in the coop games.
5) I saw this one last night and it is an issue, trying to accept an invite, I kept getting "server full" and have no idea what that means.
6) Speaking of accepting invites, when you get an invite to join a coop game, you accept, it kicks you out to the multi player menu (don't panic), then choose coop, and you will find your group. I was thinking, "WTF did I do now," the first time. It is not quick like joining the a party on multi-player but it works.
7) Last issue... at about 60,000 player on line last night I started seeing some serious lag. Dogs stopping in mid jump and guys jumping 5 feet to the side.
Aim Low... recoil, 'nuff said.
9) Watch for motion, most times someone standing still in some kind of cover is very hard to see. I have run right up on guys just standing there and been shot because I couldn't see them. I've also used that to my advantage a couple of times, 5 kill steaks without moving. Just don't stay there for long.
10 ) Spawning is strange in HQ, it's almost like you spawn very close to where you died or if you are on a squad you will spawn with your squad (Blue highlighted names above player and on lists are your squad)
11) Look out for the black dogs.... bastards!
12) Try to work with others, it seems to me that working together though these areas is a lot safer than just running through, much like the single player rounds.
13) Play the single player, it helps with weapon control, vehicle control, and picking out which weapons kick ass.
14) Don't fear the tanks too much, they do take damage pretty well, and you can't just run rampant around the map in one killing.
15) Zombies Rock!!!!

To add....

16) Conserve ammo in normal game modes, bandolier doesn't come until level 40.

17)Like Shamos said, going solo will not get you very far in objective based games.

18)Using the Second Chance perk while staying with a buddy who has it also is deadly.

19)Try all the guns until you find one you are good with and enjoy using, these guns are much different than COD4 and just because you were a beast with submachine guns in that doesn't mean you will be here.

20)It's always good to be with a squad. Its so much better spawning with your team rather than half way across the map.

21) Do not depend on your HUD. There are A TON of campers with camouflage(Perk- Same as UAV Jammer).

22) Scan the entire environment, there are way too many good places to hide.

23) Always use caution when entering a room.

24) Brown Dogs= Good, Black Dogs= Bad

25) A smart tactic might be to follow the dogs, people tend to shoot them over you giving you the opportunity for some destruction.

26) Have fun with the game, don't shrug it off because it isn't COD4. This game, in my opinion is very good and very well developed.

27) I don't know anymore so yeah, game on.