Found this list on-line, /Ive tested it and was able to find all the intel fairly easy. The only one that was kind of hard was the one you had to run over with a snow mobile.
I recommend just going down the list one by one. Start the game on recruit is also recommended so you can just worry about intel and not a difficult game.
Intel locations
Search the indicated locations to find all 45 Intel laptops:
Act I: S.S.D.D.
1. The Intel is under the watch tower, straight across from the entrance to the obstacle course.
Act I: Team Player
2. The Intel is in a classroom. Someone will announce "I think I saw one go in that classroom", and your team will go in. It is on the right wall as you enter, on a desk by the barrels.
3. As you exit the school, it is on a crate directly outside, next to a taxi.
Act I: Cliffhanger
4. Directly in front of you when Soap tells you to go ahead alone is a guard tower. Go up the ladder to find the Intel on the catwalk.
5. When you are about to enter the building with Soap, go to the previous building in the alley where the Jet is inside the hanger. Break out the window to find the Intel inside.
6. During the snowmobile sequence, when you are approximately 1850m from the finish, stop. Look for a small wooden fence surrounding some trees in the middle of the path in front of you, and a small wooden building up a hill to the right. The Intel is on the ground inside the fenced area with trees. Just run over the Intel to pick it up.
Act I: Takedown
7. Using the map, go towards the south-west corner when you enter the favela. You should find a motorcycle leaning against a building. In front of it, there is a building with an angled wall and a large window in the wall. Go through the door to the right of that window to find the Intel inside.
8. When you go through the alley and see the building with the ladder on the wall, go up it and through the door. The Intel is on a table inside.
9. Directly across from the previous Intel is a building with a small set of wooden stairs. There are a few guys inside you have to kill. The Intel is inside the building on a nightstand next to the bed.
10. Towards the end of the chase, off an alley, go in the building on the right side of the path. Go downstairs to find the Intel between two beds.
Act II: Wolverines!
11. The Intel is on the counter in the gas station after you go through the alley.
12. The Intel is inside CRB Financial (across from Nate's Restaurant), near the front door, under a sign labeled "Online Banking".
13. The Intel is on a table inside Taco To Go. Enter the building through the blown up corner.
14. The Intel is inside a dumpster (in a small brick enclosure) on the east side of Burger Town. It is visible from the Burger Town roof ladder.
Act II: The Hornet's Nest
15. Near the beginning, after you move forward from the first building, go inside the house to the right of where Soap stops in the road (there is a blue car in the garage). Go past the blue car and into the kitchen to find the Intel on the table.
16. After clearing the small lot (has a bunch of appliances and cars), instead of going right up the stairs between buildings, go left around the three-story house (floors are colored red, yellow, red), and look in the little hut attached to its side to find the Intel on some barrels.
17. As you move up the sloped street, there is a blue car on the right side of the street. In the building on that side is the Intel up on the second floor on the table.
18. When you enter the last open lot and are supposed to go up on the roof, turn to the right, and look in the window behind the goal fence to find the Intel inside a window.
Act II: Exodus
19. In the apartment office, near where the enemies are first repelling in from a chopper. It has red walls and blue curtains inside. The Intel is on the desk.
20. In the right-side building of the structure that forms an arch over the road (has toll booths), on a desk directly to the right as you enter.
21. After you cross the bridge, go into the second house on the right side of the street. Enter from the front door, then go to your right and up the stairs. The Intel is on a yellow couch above those stairs.
Act II: The Only Easy Day... Was Yesterday
22. In the room before you go back outside (shortly after breaching), the Intel is on one of the metal racks against the wall.
23. After executing "Plan B", in the room Soap goes into on the right, the Intel is on a metal rack inside the door.
24. After clearing outside, when the team starts going up the stairs, enter the room to the right (you were probably in this building before when you were told to take cover), and look under the stairs on some wooden palettes to find the Intel.
Act II: The Gulag
25. As your team moves towards the arch with the red light, go to the stone stairs before it, and look inside the room on the far wall to find the Intel on some filing cabinets.
26. The Intel is on a desk behind the large wall of monitors you encounter on your way through.
27. After you get the riot shield and leave the room where you got it, turn left, and go down the hallway. In the first open cell on the right-side wall is the Intel on a desk.
28. Once you find the person you have been looking for, turn to your left to find the Intel on the desk.
Act II: Of Their Own Accord
29. Inside the elevator that keeps trying to close (in the hallway after you enter the building), the Intel is to the right of the body sitting inside.
30. In the room with a balcony (out on the balcony is a missile launcher), go to your left as you enter the room, and enter the door straight ahead (near the portrait of Franklin Pierce) to find the Intel on a table down a small hallway.
Act III: Contingency
31. When you reach the three-man patrol standing near the fence, kill them, and go over to where they were. The Intel is about ten feet south on a crate.
32. The building labeled "33" along the angled south-west fence contains the Intel on a metal desk inside the northern door.
33. Just north of building "33", locate the stairs leading to a helipad (has blue lights on the corners) to find the Intel in the north-west corner.
Act III: Whiskey Hotel
34. When you are told to go left to the building, inside that building after the next door has been opened, the Intel is in the hallway on a couch to the left.
35. After you go up the first stairs towards the roof, the Intel is to your right on a desk. This should be about the time when the you see the flares get lit.
Act III: Loose Ends
36. Before entering the house, go behind it, and locate the small boat hanger along the shore. The Intel is on a crate outside of it.
37. In the locked room on the top floor of the house, the Intel is on a desk in front of the door.
38. In the nearest locked room in the basement, go into the arms room to the left. The Intel is straight across from the wall of weapons on a crate.
Act III: The Enemy of My Enemy
39. The Intel is immediately to your right when you begin the mission, in the front of the plane.
40. After you slide out of the plane hull and move across the street and up the hill, look for the plane pointing towards the road. The Intel is inside, near the cockpit.
Act III: Just Like Old Times
41. As you enter the tunnels, go left as instructed. After the patrol passes, kill the guard standing at the monitor, and go straight across to find the Intel on a crate just to the right of the cave entrance.
42. The Intel is to the left on a desk right before you go outside from the tunnels.
43. After going across the ridge, the Intel is in an alcove, on a crate.
44. The Intel is on the desk with soda cans after you breach the room, near where your ally is working on the computer.
Act III: Endgame
45. The Intel is at the beginning of the mission, before you board the vehicle.
