Ohhhhhhkay... as I remember it there's not too much in Sousse, other than an old town in the centre - much of the rest of it is industrial, I think. So you'll probably want to check out other parts of the country. There's one north-south train line, so I would recommend heading up to Tunis maybe for a couple of days, and visiting Carthage and Sidi-Bou-Said whilst you're there. Also, if you like beaches then take the train up north to Hammamet. The train is super super cheap and really easy to use - don't let anyone tell you otherwise! Just make sure you get a copy of the timetable, and book the time of your return trains when you book your outward tickets.
You should definitely go to the Roman amphitheatre in El Jem, its really remarkable. And also if you can get transport down south to the desert and the salt plains then thats definitely worth doing as its a completely different landscape and just a wonderful experience. Matmata is where Star Trek was filmed and where many of the people live in underground homes, and thats another great place to go to. There's just so much to see/do there I'm sure you'll find something you like.
I was there in April... have a look at
My Blog if you want to see pictures etc... or just let me know if I can help with anymore questions... otherwise have a wonderful time
