John O’Malley, SJ has a marvelous article at America Magazine on how not to understand Vatican II. I refer you to the whole piece, but as a teaser I give you here his 10 principles to avoid:
1. Insist Vatican II was only a pastoral council.
2. Insist it was an occurrence in the life of the church, not an event. (An “occurrence” is something that happens but has no lasting impact, an “event” does.)
3. Banish the expression “spirit of the council. (My favorite)
4. Study the documents individually, without considering them part of an integral corpus.
5. Study the final 16 documents in the order of hierarchical authority, not in the chronological order in which they were approved in the council.
(This one and the previous one were points I had never considered.)
7. Stick to the final 16 documents and pay no attention to the historical context, the history of the texts or the controversies concerning them during the council.
8. Outlaw the use of any “unofficial” sources, such as the diaries or correspondence of participants.
(This is part of understanding the Spirit of the Council.)
9. Interpret the documents as expressions of continuity with the Catholic tradition. (Kind of hard, in some cases.)
10. Make your assessment of the council into a self-fulfilling prophecy.