The biggest lesson (I think it was in that book) was that you're being hired as an expert on a topic. to be a Successful expert you must A) have an expert level of knowledge about the topic and B) LOOK LIKE you have an expert level of knowledge about the topic. Those are two separate, but essential things.
2. Go for 70-30 split of listening to talking.
3. Read Million Dollar Consulting by Alan Weiss
4. Make sure to read a lot in the early days, but don't expect to get more than two or three insights from any particular book (for example the insight in the Weiss book that has proven most useful was "Clients that are difficult in good times will be nightmares in bad times". That has been true in each and every case in 17 years in business)
5. By the time you're in front of someone (physically) your primary job is not to sell them on anything, but to de-risk your offering to them.