Choose your travel dates. The weather in Morocco is wonderful throughout most of the year, though most tourists choose spring or summer to visit.
Book your travel. The only way to travel to Morocco directly from the U.S. is to fly. Only one airline has direct flights to Morocco, Royal Air Maroc, with flights from New York to Casablanca and Rabat. Several European airlines have flights from the major cities in Europe to Morocco, so you can fly to London, Paris, etc. and connect to a Morocco-bound flight if that works better for you.
Enjoy your stay. Morocco has excellent roads, and car rentals are readily available. The country also sports a wonderful public transportation system, with trains from Fez to Casablanca, and Casablanca to Marrakech, enabling you to easily visit areas outside the major cities.