One motivational trick a marathoner-friend taught me when I began riding centuries is to "dedicate" parts of your ride to your loved ones and call on them in your mind when you need a mental boost. For example, you could divide your ride into 3 10-mile legs, each for a different friend or family member, and think often of that person rooting for you during that segment.

One of the best tips people have given you, Nubie, is to pace yourself. Start out easily and slowly, and settle into a comfortable rhythm. When I've gotten into trouble on long rides, it's usually been when I have gone out too fast. This typically occurs when I'm riding with stronger cyclists: strong at the start, I keep up their pace, not even thinking about how much of my energy I'm expending that early. My mantra, when I remember it: "It's a ride, not a race."

Oh, and enjoy your ride. That's the most important advice of all!