Ok, well I can't find the name of our tour guide, but I'll ask my husband if he has that later. He keeps everything.
As far as attire, I kept it pretty modest while I was there. I usually wore linen pants and a not-too-tight top, but short sleeves seemed to be fine. Marrakech is very cosmopolitan in that it gets many European tourists, especially French, so if you do wear shorts they will not be shocked.
Definitely go to the souk. (Djemaa el Fna) It's both crazy and amazing, and wander around the vendor stalls checking out all their stuff. I picked up some cute caftans for the beach and a bunch of colorful scarves for next to nothing. You'll see snake charmers and people with all sorts of crazy tricks. Tip: don't let them put a monkey on your head for a picture. Gross.
We stayed at La Mamounia, which is this old historic hotel in the center of town. There is a huge, beautiful enclosed garden there, and several nice restaurants. The Morrocan restaurant at the hotel is fabulous for a fancypants night out. Eat there if you don't stay there. It's lovely.
Dar Si Said is worth a trip. It's an old palace that is now a museum of Moroccan crafts. I also liked El Badi Palace and everyone goes by the Koutoubia mosque (it's near the souk). You may walk around it but non-Muslims may not enter. It's a lovely setting, though, with huge gardens nearby.
Don't do the Agdal Garden. It's not worth the effort.
Just so you know, the entrepreneurial spirit is alive and well in Morocco, let's just say. Be prepared to say "No thank you. No. NO" a lot. They were more assertive there than anywhere else I've been, and I've done a fair bit of travelling. Maybe assertive is the wrong word -- no one hassled me. Insistent. That's it.
If you find the time to leave the city and go to Essaouira (or Agadir, or anywhere in between), I'd be happy to give you my thoughts. There are some fantastic things to see and do.
Have fun!!