Murder of Crows
Explorer
I did really like those Greyhawk novels with the Justicar and his hellhound pelt that skinnydwarf mentioned.
I also liked the Night Angel trilogy by Brent Weeks. The main character is an assassin, which you could take some elements from for a thieves guild.
I also liked the Night Angel trilogy by Brent Weeks. The main character is an assassin, which you could take some elements from for a thieves guild.