There are numerous agencies in Madeira which will arrange walking tours (levadas) for you. You can find some advertised in the Madeira Times, paper. These are much cheaper than arranging through your hotel travel rep. You dont have to go to the north of the island as the mountains start in Funchal! The only flat bit in Madeira is the airport runway. Walks range from easy ones for absolute beginners to the more adventurous ones. The levadas are waterways built in the 19 century generally by slave (white) or criminal labour to bring fresh water down to the coast from the mountains. You will have no problem making arrangements.

Thanks for your reply. Sorry couldn't reply earlier. I will definately looking at booking Madeira then! Good to know that there are things you can do that don't require a car!