In the past year, I've been out with four different guides. The big key is to figure what you want from the trip and narrow it down as much as possible for the guide. For example, "I want to catch fish." is pretty broad and will work, unless of course your goal is to catch trophy fish. Then you might set yourself up to be disappointed.
Also set your ego aside. This is not a competition between you and the guide. Your past fishing accomplishments really won't have any relevance. Your skills will, but those will be on display from the first cast. I have yet to fish with a guide who hasn't helped me hone my skills, but I asked them for the tips. They work with hundreds of people a year and see good, bad, and ugly. They also pick up tips themselves, so use them as a resource.
Finally, when you are on their boat, that is their investment, office, home away from home. Respect it. Don't toss cut line on the carpet, step on the paint, or poke around unless invited to do so. Oh, and don't ask to smoke. Many guides will say Ok and let you, but deep inside, they are waiting for ashes to hit their carpet and melt it.
