There are no tricks to cruising. You simply go and have a great time! (As long as it conforms to the cruise line's terms and conditions, of course.)
I agree with Dave that you should book through a travel agent that has expertise in cruising. Ideally, you'd want one who has passed the certification requirements of the Cruise Lines International Association (CLIA). Click
HERE for its home page, from where you can enter your ZIP code to find a CLIA-certified agent near you.
I see that you got some more great tips in a couple of other threads, such as the one on embarkation. We're happy to help with more questions -- just be more specific so we can be sure we're addressing the topics that interest you.