Start in Bree. Hopefully you know how to get to Bree as it is one of the first places you will quest. You can fast-travel (for free) to Bree from Thorin's Gate, Celondim and Michel Delving and if you have a personal house you can use "Travel to Personal House" to get back to one of these cities very quickly.
If you have already explored some of the eastern lands then the stable route from Bree to Rivendell is:
East Bree -> The Forsaken Inn -> Ost Guruth -> Rivendell
If you have no stable-routes yet then:
Make sure you have the East Bree stable route
Exit Bree through South Gate and follow the main road east into the Lone Lands
Take the Stable Route at The Forsaken Inn
Then follow the Great Eastern Road east until you see the ruined city of Ost Guruth to your north
Take the Stable Route at Ost Guruth
Return to the Great Eastern Road and continue east, across The Last Bridge and into The Trollshaws
Ride east through The Trollshaws until you see a rough path to the north (33.4,15.6) turn off the main route
Follow the track through the woods to the ruins of Thorenhad and talk to the stable-master Breglobor (31.7,15.0) to get the stable route.
Return to the path and continue east to the Ford of Bruinen
Climb up the bank on the far side
And turn left at the top
About half way along the ledge look for a path to your right with doubles-back on your route and heads up hill and take it
Take the upper-left path as you reach the top of the hill
And follow the path around to the left
When you come out onto open ground continue straight ahead and bear right around the rock formation
As you pass a Mustering Horn you will see the remains of an old flagstone path
Stay on the path and follow it through the hills
Until you reach The Gates of Imladris
Head through the pass and down into Rivendell - you've made it!
Then follow the Great Eastern Road east until you see the ruined city of Ost Guruth to your north
Take the Stable Route at Ost Guruth
Return to the Great Eastern Road and continue east, across The Last Bridge and into The Trollshaws
Ride east through The Trollshaws until you see a rough path to the north (33.4,15.6) turn off the main route
Follow the track through the woods to the ruins of Thorenhad and talk to the stable-master Breglobor (31.7,15.0) to get the stable route.
Return to the path and continue east to the Ford of Bruinen
Climb up the bank on the far side
And turn left at the top
About half way along the ledge look for a path to your right with doubles-back on your route and heads up hill and take it
Take the upper-left path as you reach the top of the hill
And follow the path around to the left
When you come out onto open ground continue straight ahead and bear right around the rock formation
As you pass a Mustering Horn you will see the remains of an old flagstone path
Stay on the path and follow it through the hills
Until you reach The Gates of Imladris
Returning to Rivendell
Once you have discovered Rivendell there are a number of ways you can return quickly:
- Set your milestone to Rivendell!
- Purchase 'Return to Rivendell' from the LOTRO Store (295 TP, unlimited uses, lvl 10+)
- Purchase 'Map to Trollshaws - Rivendell' from the LOTRO Store (10 TP, one use, lvl 20+)
- Obtain 'Return to Ost Guruth' by achieving Kindred with the Eglain then take direct stable-route to Rivendell
- Hunters - Guide to Rivendell (lvl 46)
- Wardens - Muster in Rivendell (lvl 44) or Muster in Ost Guruth (lvl 26) and then take direct stable-route
- Elves - Return to Rivendell (Racial trait, lvl 29+ & Enmity of the Orcs 2)