If you have any flight points in this just take the flight point and start there. This looks like a lot because I'm starting you at any of the four major cities with no flight points. Many locations are spelled incorrectly because I'm too lazy to check them.

1) Get to menethal harbor

From Darnassus get out via the teleport to rut-therian village, from there head to the second night elf zone either by boat or flight, and in that town take the boat to menethal.
From Exodar take the boat from the small docks around the side/back of the Exodar to the second night elf zone, and then the boat there to menetal.
From Stormwind take the tram to Ironforge and then:
From Ironforge leave the town and head around the mountains to the east. Travel through the tunnels to the second dwarf zone(Loch Modan I think). From there go north and through more tunnels to wetlands. Follow the road to menethal harbor which is at the west side of the area. Note: If you don't care about getting the flight point then take the turn in the road going north to arathi.

2) Get to southshore

From menetal leave via the road and follow it east until you get to a turn that leads north, which will lead you to arathi highlands. Following this road and staying west when it turns leads you to hillsbrad foothils, however you should pick up the flight point at refuge pointe which isn't far off the road. Once in hillsbrad keep going west until you cross a bridge, then you'll be going south to southshore and grab that flight path.

3) Get to western then eastern plaguelands: light's hope chapel

From southshore follow the river north all the way to western plaguelands. There is flight point at a small argent dawn outpost shortly after you enter western plaguelands. From there go north, following the road while it's safe, until you get to another road that goes east and west. You'll have to go around(west side) a ruined town filled with undead if you don't want your lowbies to die. Go west when you get to the mentioned road and it will lead you into eastern plaguelands. Keep following the road until you get to a small town that is filled with undead. Going around the northern side has only a few mobs but you'll be close to a chasm that you don't want to fall in, while going around the south side is longer and you'll probably still aggro some stuff. There is a road going east and a road going north out of the town.* You basically want to go in the middle of them. You should come across another chasm shortly. You want to be on the east side of the chasm(go around the south side if you end up on the west side of it), and then go north a little bit and you'll come across light's hope chapel, an argent dawn camp with a flight point.

4) Get to stratholme

From light's hope chapel you want to get back on the road going north out of the undead filled town(marked with a * from the previous section). You can go around the south of the chasm the way that you came, but I believe you can also go north and then head west when you get to a river but I'm not 100% sure on that. Either way you will come to a bridge, and shortly after you'll come to a fork where you should turn west. You'll see a tower, and the stratholme service entrance is not far past the tower but you need a key that drops off of a boss in strat to get in there. Continue on the road if you want the main entrance. It won't be long before you get to an area with undead on the road and you'll have to do some fighting. When the road forks go north and you're there.