Hi! The most interesting thing about this exam you should know is the outline, all the questions divided into several topics, types of all questions match the outline.
Yes, there was questions about SONET bytes and ONS OAM&P.
I recommend you to find Boson's test on SONET to get familiar with its questions, my SONET skill got high after it. If you won't find it - please contact me - i'll send you this program. Then you need to order some books from Ciscopress: 1. Self-study: Building Cisco Metropolitan....(METRO) 2. Cisco Optical design smth (this book you already have).
3. ONS 15454 SONET MSPP Engineering Planning Guide (very useful in all the things). These books cover almost all the exam's topics: POS, DWDM, DPT, Sync Status Messaging in SONET (there were questions with diagrams - you'll need to solve them quickly) and others.
According to TL1 - you don't need to learn its commands - just few mainline questions about it and SNMP, CORBA (ports, architectures).
As for me - i've started with outline and Inet docs from Cisco.com (i mean without books i've mentioned earlier), prepared for two months self-study. It was hard enough to answer detailed questions like "How many STP instances/ MAC addresses etc. are supported by ONS cards", so you should pay attention to all the supported features and numbers (e.g. how many rings SNCP supported, what port is used for PGP protocol(topic POS)).
The best way is to divide all the topics and work hard with it.
Sincerely, Artsiom Maksimenka