New to multi player gaming. Can someone direct me to where it explains what all the screens mean? The one that mosy interests me is when you finish a match and it brings up everyones stats. What do all these things mean? i sometimes have a yellow type hat thingy or a red thingy, still trying to work these out. I am also a little concerned that i get killed with one shot majority of the time and when i hit an oponant it takes many shoots to kill. Is this something that comes with time or am i doing something wrong?

Also any help in passing on knowledge would be great. there is a provission for max radar, radar jammer, nano suit jammer, ceph airstrike, max nano suit and orbital strike. How do these work during game play. I have seen them being used but have no idea how to use them.

There is part of forum Gameplay&Media that has a lot of threads that could help you with this game.

Stats after match show you how many kills you achieved, and how many times you died. Also, there is number of assists, and that last number even I don't understand xD I think it's ping related or something... It's in this order: score, kills, assists, deaths, ping.
I don't know what exactly you mean by yellow or red thing, but in match results screen there are top 3 players shown, and there is also one screen showing all players results, that yellow one is you. Maybe you mean red icon left to player in top 3 screen? It appears if in top 3 players there is someone from the enemy team.

About that one-shoot-kill, it's probably headshot. Maybe there was aimbot cheater so you got shot in head many times during the match. But also, experienced players are trying to shoot in the head (because it's opponent's weakest point) or at least upper-body. As you are building your experience in Crysis 2 multiplayer you're probably get better at aiming, so head-shots will become easier to achieve.

Max radar, ceph airstrike, etc... are support bonuses that are available when you achieve killstreaks (number of kills without deaths in between) and collect dogtags from your dead enemies. For example when you kill your enemy and collect his dog tag, there will be notification on the left side of the screen showing you have 1/3 dog tags, that means you have one out of 3 dog tags that are needed to activate Maximum Radar.
When Support bonus is available, you need to press "P" key to use it. If it's Orbital strike (5 dog-tags), you need to point in which direction orbital strike beam should go (you direct it where are most enemy players are moving). The same thing is with Ceph gunship airstrike (7 dog-tags).
There are some modules that lower the number of dog-tags needed for some support bonuses, but I advice you to read other threads that explains this thematic.