Hrm.... I definitely learned how to have fun and how to roll in a group/raid from Shakdursh. (started out in pvmp as a creep)
Learned how to throw fear of dieing out the window from Punnkd (and how to macro my "I'm rezzing you stay put" thingy =P )
Learned how to spar on an LM from Rahb. (indirectly, by watching him)
Learned how to throw tea parties from Gas. =)
Learned how to efficiently farm the various #### on the map for quests as a creep from Pulchra.
In a way I learned how to hate another player from Daec. ^_^ (doubt he even remembers that event from way back when I first started -- long since dropped aside from me being amused to remember it -- hi Daec =D )
Learned how to embrace being in a kinship from Maie. Was very resistant due to some previous experiences before I found Haste via her. =)
Learned how to pull all kinds of little sneaky tricks and tactics from Rahb and Falcon.
Learned how to be a crazy dervish of chaos on my burg from watching Bing. I miss him.
Wouldn't say I had a specific mentor but I've certainly picked up things from just about everyone. =) *salute* I'm sure there's some folk I missed.
(Retired from Freepside)
Freeps: [color=#9999ff]Elerene[/color], Ikaelus, Graedus, Ziebold, Saracia, Zandiran, Erunir, Jaenda, Derwisch, Gwendilas
Creeps: [color=#ff9999]Ishtiluk[/color], Sranakh, Fangborn, Tolorath, Oroknash, Logarat