I have currently found two of the five Taris datacrons, and they were difficult to find. So here is how to find them!
Datacron located at X: -1515, Y: -253
For this datacron, you will need to run along the walls to get to the platform above the holocron so you can drop to where the holocron is. Follow the ledges on the wall from the ground-this will help you find the area where the ground is raised enough to get onto the wall. Once you are successfully on the wall, run until you reach the crashed ship that has a broken pipe running to a different section of the wall. Run across the pipe. Once across, follow the wall until you reach the large platform under which the holocron rests. Find the hole in the platform that opens up to the thruster next to where the datacron is located-from there, simply jump to the holocron's location.
Holocron located at X: 1187, Y: -571
This one is incredibly simple to get to. Get up onto the hill where the pipe runs from the side of the hill to the group of ramps where the datacron is located. Run across the pipe. From there, getting to the datacron only requires you to run up the ramps.
Hope this helps!
Added by: MasterofPokemon Jan 1st 2012, ID#16829