I lived in or near Anaheim for most of my life. I worked there while I went to college, and my family has had annual passes for as long as I can remember.
My children would rush home to do their homework so I could take them to play on Tom Sawyer's Island afterward. Disneyland was their backyard.
I feel for people who can visit for only a day. There is so much more to the place than the rides. The ambiance is so pleasant with every little artful detail painting a picture of a faraway time or place. We stroll through Disneyland without going on a single attraction during most of our visits. Locals will ride only if the ride is a "walk on" meaning that there is no line. But we come for the fantasy escape, the music, the dining.
There are new events all the time to attract the regular annual passholders. I would encourage first time visitors to go to the Disneyland website for tips on how to make the most of your trip. Top tips:
1. If at all possible, visit during the off-season (not summer!) or you will spend more of your time in long lines.
2. If you must visit during peak season, map out the rides you must experience and then make a beeline for the "fast pass" tickets for each attraction. This will save you waiting in long lines.
3. Take a look at the daily schedule so see which parades or other shows you'd like to see. If you'd like your little one to participate in the Jedi training show, for example, choose a time and arrive early! The spots are limited. And be sure to warn your young padawan that he still might not get selected.
4. As for dining, you'll need reservations for some of the dining establishments (Blue Bayou, etc.)
I can offer more but this is a start!