A fellow Moroccan traveller forwarded an email from a friend that only gets me more excited about the trip!
You have made an incredible investment. Morocco was one of the absolute coolest places I have ever been. We went to Fez, only for about 4 days but there's a lot you can pack into a short period there.
Cities in Morocco and north Africa in general are incredibly old, so the way they are structured now is usually split into two parts. Every city has within it an Old City (the "medina," which in Arabic just means "city") and a New City. I don't know where you're going, but you'll likely be spending most of your time in the old city. These areas date back hundreds and hundreds of years, and are usually surrounded by an enormous wall with 3 or 4 main entrances, remnants of the ancient fortress city structure. There are also no cars or trucks allowed in the old city, mostly because even the main old city streets are often no wider than 15 feet (be warned if you are claustrophobic; some of the smaller residential streets feel like attic crawl spaces). The Medina in Fez, which used to be the capital, is the largest urban area in the world with no automobiles.
The Medinas are also more conservative, traditional areas. You have to go into the new city areas to find any alcohol, for example. And there are cats everywhere. In Morocco they are like pigeons for some reason.
The new city is pretty straightforward though: wide boulevards, grocery stores, gas stations, but still quite beautiful.
I don't know if you're going with a group or have some sort of tour package, but my advice would be to plan ahead to get some solid tour guides. Morocco has a huge tourist industry, so there are a ton of tour companies, big and small, that have guides certified by the government. When you're walking around the old city, every other Moroccan dude tries to be your guide. Don't let them. They will even follow you along for awhile. MOROCCANS ARE AGGRESSIVE. Don't get intimidated. Be firm. It's just an aggressive, bartering, market kind of culture.
But if you have a certified guide, the random street guys will take the hint and leave you alone for the most part. Without a good guide you will get lost in the old city. At least at first. There are no two ways about it really.
(The way it works, typically, is that the guides will have a set program in mind for you with cool touristy places to visit [like shops, tanneries, pottery kilns, tourist mosques, scenic areas, etc.]. Whether the guides are certified or not, they will probably get a commission from the places they take you, so just bear that in mind. This is a totally legitimate business practice [if the guide is legit], but it can be rather manipulative too.)
I've written way more than you wanted to hear probably. I loved Morocco though, so it's fun to give advice. Let me know if you have any more questions!