Always say in the shadows, plants, behind trees, etc. and you can kill anyone. Also remember to always use silent weapons. If you like range killing get the sr-25 sd to kill from afar or if you just want to put bullets down range get a assult rifle. Hope this helps.
Hopefully this will help some one, when you start the level off you kind of in like a corner of rocks, but if you walk straight ahead to the other rock just on the other side of it there is a riddah, he is kneeling in the bush, but if you sneek up behind him and kill him, you have a really good veiw of the hut!.
Also : It is easier to see him if you have you night vision goggles on. ( press the ^ button twice).
On the second level "GhostTown" take out the bad guys by using the scilenced sniper rifle or the scilenced sub machine gun . then look on the map to find the generator once found turn it off so the alarm doesnt go off an theres a place some where around the generator. this is where the lap top is but watch out becaues there are bad people every go up all 3 flights of stairs an go out side on the roof, there is a door open it take out all guards an get the lap top out make sure to turn off the alarm. have a great time snipers
Ok what you do is when your online you go to a part where theres a glitch in the wall. Then plant a claymore about 5 feet away from you make sure you have your back to the wall where the glitch is. Then blow up the claymores and your person will fall into the glitch and just keep falling non-stop! It's pretty funnny.