Lee the best advice I have is to read the dry, boring book. It will be a chore, but it helped me when taking the code book exam. Reading through it will help you figure out where everything is in the book, then you can study the questions being asked and know where to go to find the answers. Example: What is the minimum fillet weld size for a 3/4" diameter stud when manually welding the stud? Since the question is talking about stud welding, you know to go to Clause 7 and start looking for the answer.
Another example How much preheat is required to weld, using a low hydrogen process, a 2" thick ASTM A 572 gr 50 base plate to a ASTM A992 column shaft with 1" thick flanges and 5/8" thick web? The question is about preheat so you know to look in Clause 3 and find the Min. Preheat and Interpass Temperature Table to look it up