Hello,
I don’t have any book for logfile interpretation, i’m not even sure it exists unless it was created by some optimizers team. Basically, you just need to have a practical knowledge of dynamic behaviour of the MS (frequencies/interference, measurement reports, handovers, call setup procedure, etc) and perform drivetests as much as possible.
The more you’ll do them, the better you’ll understand them, that’s for sure.
Good luck,
regards,
Pix