Spec Ops: The Line

The first intel item is located once you reach the first objective of the game, when it asks you to "Locate the Beacon". Once you reach the beacon, your team mate will begin to use it. From it's location turn around 180 degrees, and head towards the humvee with a map pinned to it's side. Pick up this intel, and you will unlock this achievement.

View these videos for more intel locations:
Part 1:
Part 2:
Part 3:

I made this video to show the locations for all of the intel items hidden throughout the campaign. You will also get the following achievements on the way:





These aren't hard, there are only a couple that might be missed and I've only made a guide because I was recording anyway.

Hope this helps but if there's anything I've missed please leave a comment.