User blog comment:Alduin's Bane/Questions (Skyrim)/@comment-30303790-20120905204952

Well to answer both the last two questions, I would recommend Discerning the Transmundane. The quest is interesting enough, and you net the Oghma Infinium.

If you want a quick level up, there's no better way as the OI can help you to level out every skill to 100 in a short amount of time. Definately useful on console, though you may not need it with access to mods and controls on the PC.

Also the thieve's guild quest has some interesting armors and a few weapons of interest, and it is the best faction story arch, at least in my opinion. . .and I don't even play as a thief character.