Well, it's a long time since my first trip in 1992, but my 'learns' were:
Don't bother with the welcome meeting - you'll be awake at the crack of dawn, so take the opportunity to get a march on the crowds and hit a park on your first day;
Don't try to blitz everything. We rushed from ride to ride, following the tour plans in the guide books, which, on the whole, are written for Americans (who tend to spend 3-5 days there at a time) and focus on the busiest periods. Take some time to soak it all up and 'smell the roses';
Don't try to do it all. Concentrate on your "must do's" - for me, the four Disney parks and two Universal parks. For most families, that probably means a water park or two and, if you're animal/wildlife lovers, Sea World too. I do really like Sea World and it's even better these days, but there's so much to do that it's still probably the first park which would get dropped in a contest with the other major parks;
Realise that, no matter how much the mind is willing, you will need some 'down time'. For me that's shopping
teeth: ), for others it's probably relaxing at a water park, or by the pool.
