Hey, I just started playing Morrowind not long ago and I'm still trying to find a character I really like. So far my favorite is a lvl 11 crusader, but I can't find that stupid book"Progress of Truth" for the Main quest. Anyone want to tell me where I can get a copy?

You can find a copy you can buy from Jobasha at Jobasha's rare books(duh). Or you can steal one from the library of Vivec. Look around, just keep an eye on the wandering ordinators.

Those are the ones I remember right now.

There is also a copy in the Telvanni Tower (Telvani Canton, Plaza Level) and in Arelas' house in Tel Urvith. There is one in the Secret Library in the Temple, but the one in the regular library is easier to get.

Umm that one book store in Vivec Foreign Quarter where you escorted that Argonian Morag Tong agent too sells one.