Ok I am from there. lived there. Few pointers ... try not to drive there, espcially since you havenever been there. You will go crazy. Us moroccans do not drive by speed limits and it can be a nightmare trying to figure out whos going where. besides, the grid formation of streets here in the US we are so used to here, will serve you no good there.
The best thing I would suggest is RENT a taxi guy for the day or weekend. They are 2 kinds, the legal Taxis and the illegal taxis. The difference is in price. The illegal taxis will charge less and they tend to be good people with no jobs, so they use there cars to transport people. The illegal part is that they do not have a license as taxi drivers. So if they get stoped by cops they get fined. You get to walk away unscathed. But thats FAR and few in between when that happens. In 10 years of riding in the illegal taxis, we were stoped i would say 7 times. 1 resulted in a chase which was fun.
I digress. But really they are just a good as real taxis. If you want to feel super comfortable, get a standard real cab and tell him what you want to do. But that means he has to go with you everywhere. Not sure thats your plan. You might have to pay for his food etc but it will be cheap.

If this sounds like too much of a hassle ... then just go for the original idea of renting a car. Just be prepared to get lost and sometimes frustrated during traffic jams. But thats part of the chic ness of the place no?

Or you can use the train which is pretty darn good. Just keep an eye on your belongings of course. I dont say that cause it Morocco, I say it because if you were on BART here and left your things for a few minutes it will be gone ... trust me. Keep in mind you are a tourist, and you will bring attention to yourself. But if you show respect for the culture and habits ... it will open doors you have never dreamed. Foreigh cultures (regardless where you go I belive) LOVE and will help any one that shows interest and respect for the country he is visiting. They will go out of their way to help you. Be weary a bit of fast talking young guys with a shine in there eye ... those are salesmen ... which mens they might have an agenda.

Price negotiations: If you go with either taxis, NEGOTIATE PRICE before leaving. And repeat it over and shake hands over it (like farmers). You might give half then and half later, your call, but again shake hands over the deal. Smile and look natural like youhave negotiated before.

I think thats it? good luck and have fun over all. try the snails I dare you! They are delicious.