Basicaly everything Phelios said..If I may add my 2cp.
Note* This is by no means a definitive list of quests that are implemented, this is only what I have come across..I am sure there are many others available.
The ranger guildmaster (in erudin) doesn't seem to offer a ranger specific quest.

(that I know of).
Not sure all quests are accessible for specific classes....
I haven't completed too many quests..
Completed:
Warrior Tunic Quest (Talk to warrior trainer in Erudin)
Druid Amulet Quest (Talk to druid at circle in mistwoods)
Shark Hunt Quest (talk to Erudin Defender at the Docks) (the blood pearl from this quest is used to start the Bloodletter Quest)
Erudin Symbol of Honor Quest (talk to Capt. Utvoz in Erudin, and collect the four idols dropped from Warrens Kobolds) (This EQ you can use as a Ranger, and is well worth the effort).
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I've started these but haven't completed them yet, myself...
Bloodletter Quest (Give the blood pearl from the Shark Quest to Umma Stormhammer (sp?) at the Erudin Armory, to start this quest)
Doll Quest (Talk to the distraught woman in a house in Mistwoods)
Boots Quest (talk to the Gnome in a house in Mistwoods)
Potions Quest (talk to Vetiar the magnificent in Erudin)
Research Quest (talk to Anastaisa in Valley of Erimal just outside of Warrens)
?? Quest (talk to Grabslosh The Festering in Valley of Erimal)
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There are many others..I believe a cleric quest is offered by Priest Jezen (sp?) in Erudin..Also most of the Trainers in Erudin (and I assume Thurgadin...turning in Dwarf Heads is one I've heard of) offer quests..
There is also The Twilight Sea (In the Froglock Fort and in Taldor Malath I have seen quite a few quests, but haven't started them yet so I'm not sure if they are high lvl or low lvl..)
Just try and Hail every NPC you come across, and keep track of what you need to do/collect for each one as you lvl up...
Hope that helps,
~DarkArtist