Sniping Locations & Procedure
Sniping locations are noted in red and green spots on the map.
Green denotes better spots on map. Red denotes dangerous spots to avoid if possible unless you have no where else to snipe from. Green spots are also where I usually hide to kill the newbie snipers at the Red spots. I will go through them 1 by 1.
Procedure:
First I'd talk from perspective as Mec sniper.
A.When the map begins, it is better to jump into an open squad in the final countdown seconds to grab the sniper rifle first & then leave to make a sniper squad. Before you deplore this behavior, think logically because this is justifiable and advantageous to the team. Firstly, if you know that you are very good as a sniper, it is better that you get the kit faster than the newbies who will take it into the frontline & lose it or who don't know where to snipe from. If the kit is picked up by the enemy, you will have 1 less sniper kit respawning until the enemy dies.
Leaving the squad serves to free up a space & besides, a sniper is useless to a 6 man squad in the frontline due to the 8s rule. Typically distance for attacking in frontlines is under 300m. A normal rifle is much faster to deplore and kill. If you say sniper can spot of the squad he is in, than that's really a waste of 1 spot. For spotting, just use mumble instead on the Squad Leader channel to help guide the SLs.
Also in a 2 man squad, only 1 person can get the sniper kit, hence in order to make a full sniper squad with 2 sniper rifles, 1 sniper rifle must come from another squad.
Hence a good Squad Leader understands this and should not begrudge someone coming into his squad to take the sniper kit.
B. Once you have the sniper kit, take a logistic truck and go with the second sniper. Or you can walk to the sniping spot at a7k5. I usually take a truck as I will require the crates to refill bandages & ammo fast. You will not want to take a 10 min walk back to base and then another 10mins back to the mountains. It is more effective for yourself and hence your team to be able to continuously fire at a7k5. Do not take the transport truck in the beginning as your team requires it to rush for caps. Logistic truck is better as a) people tend to abandon them at the frontlines b) the team can easily use the transport trucks to reload at main. Resupply is much faster as Mec. And in the first 5mins, they can take all the transport trucks for West obj & East obj with 1 logistic truck left over.
In my map, the path is denoted by the yellow line. Stop the truck at a8 where it is in the picture, drop the crates, and hide the truck near the mountains so the eventual cobra can't find it. Subsequently take your time to walk into A7k2 where the yellow line ends. There is a gentle slope there where you can walk up slowly to A7k5. There is no need to jump. If you are jumping, it means you are on the wrong path upwards.
Also there is no need to rush as everyone is moving towards their spots. If you really do get up there fast, you might get a surprise in the form of US choppers dropping off a sniper squad on your location very soon behind you as they might have the same idea to snipe from a7k5. Also there is not much to see at this point as US will be busy securing Docks objective.
Now I will go through the spots
Spot 1) This may be the best spot in game. You overlook everything on West & East caps, especially the mosque, the construction site, the roofs of every major building. The bulk of the tug of war will be played around this East & West objective anyway. If you arrive at the spot late or later in the game, you will find enemy newbie snipers along the ridgeline of the Spots 3, 4, 5 and 13. Spot 13 is a bit far to spot but you might see the silhouette when he makes his way south.
If Mecs lose East objective and majority of enemy is in South, you can proceed east along the ridge line to spot 12. This is a bit tricky and involves a lot of jumps & double jumps. Train first on an empty server.
2) Just west of Spot 1, this is the location to relocate to if enemy starts to fire upon Spot 1. Just go back down the hill and climb up again to Spot 2. This spot is slightly more obvious to the enemy due to how the graphics is drawn.
The downside to Spot 1 & 2 is that, should someone decide to sneak in to backstab you, there is nothing much you can do except defend with pistol or try to escape and hide by travelling west from Spot 2 or east from Spot 1.
3) This is a typical spot for newbie snipers from both sides. The crane in construction site is the most obvious position to spot and kill a sniper. Avoid using.
4) Again a typical spot for both sides. If you hear a single gun report while you are at Spot 1, quickly observe and counter snipe these guys at spots 3, 4, 5. Avoid using.
5) A typical spot for US side. Its a silhouette shot from Spot 1 but you should be able to hit it with no problem. Avoid using.
6) Typical newbie spot from top of the hotel. Everyone can spot you easily and kill you with a normal rifle. Avoid using.
7) This is top of the warehouse and used to be a lesser known spot and quite interesting for a US sniper to use. You can't really kill a lot but its good for spotting vehicle movement. Avoid using as US sniper.

Mosque tower. Again a newbie spot for any sniper. Easily spotted and sniped at. Avoid using.
9) This spot is partially covered by the green line. Its meant to denote the roof of the other hotel. It is a lousy spot for Mec as you cannot see much unless the US side has pushed beyond East objective. Easily spotted and killed. Avoid using.
10) This is at the Mec Fortress. You can't do much as a sniper here as you will see zero enemies unless they have already overran to South city. Again easily spotted and killed, especially by attack huey or cobra. Avoid using.
11) It is by the tower near the Mec main. It is good only for sniping onto South city when the enemy has overran that position. Interesting note, you can actually walk along the entire ridge line to a7k5 if you want to. Only spot to defend as Mec sniper really.
12) Already mentioned. This is used for overlooking onto East and South objectives as US sniper for offense or Mec sniper for defense.
13) This spot is really debatable. Most US snipers use it as their first spot as it is easy and fast to get to from their carrier. However I really dislike this spot as it is difficult to travel southwards without coming down to ground level which is dangerous territory for a sniper. Also most people know to fire towards this location when they get sniped at North Obj and there is no place to hide at the hills on 13.
I did not go further beyond North Obj as it is pointless. Once Mec team captures north and push to docks, it is almost game over for US team.
Paradoxically, only when your team is doing badly at pushing and capping, is when most of your kills will come in. When the Mec team is extremely efficient, you can maybe pick off 1 to 2 squads before USA gets pushed back to docks.