Scout Dinardo is dead. You must collect his pieces of his report from the undead around Ruins of Karana.
Kill skeletons that are at least level 27, either solo or heroic, for 5 uncommon updates, outside the of the rear entrance to Ruins of Varsoon ( -486, 6, 1048 ) /waypoint -486, 6, 1048. Skeletons inside the Ruins of Varsoon also seem to work.
Scout Kaylinn can be found on the ledge just north of the Coldwind Shores Cemetery, west of the gnoll towers overlooking the gnoll camp on the north edge of Thundermist Valley at ( 1342, 12, -226 ) /waypoint 1342, 12, -226. Note - this is also the spawn point of Windfeather, and it seems that if Windfeather has recently spawned, then the scout will depop, so try looking again in 5 mins.
Scout Deeryen can be found behind a boulder on a small spur of land occupied by giants. Right-click the boulder and choose Look around the rocks. The exact location is ( 902, 0, 1174 ) /waypoint 902, 0, 1174.
Scout Eldyum must be spawned. This is a 3-wave ring event. Stand near the griffon station end of the Village of Thundermist. Start the ring event by walking on the rock nearest Defender Bolaris/Defender Rowan at ( 604, 6, -163 ) /waypoint 604, 6, -163. After the third wave the scout will then appear among next to the rock you walked on to start the ring.
You no longer have to kill (or even attack) the third wave; you may allow the guards to take care of them. The scout will spawn after this mob is dead.
Scout Cendalya can be found on a rock ledge watching the water near the Siren Temple.
This is at the southern end of the west coast beach. The exact location is ( 1410, 0, 308 ) /waypoint 1410, 0, 308.