Well, the first question I would ask is "How are you getting there?" Its the furthest point from Funchal and the airport that you can get There is not a lot to offer the tourist either apart from seeing some "killer whales" during the season when they swim past. It is also known for being the wettest part of Madeira! Sorry to sound so doom-laden, but unless you are going to hire a car and travel around the north of the island, I can't recommend Porto Moniz as a place to stay.
Perhaps someone who has actually stayed there may offer more information as I lived on the SW coast of Madeira.

Porto Moniz is a smashing place with a super open air pool but is a long way from Funchal where all the action is, we stayed at Encumeada last May and travelled to Porto Moniz on the public transport, a car would be neccessary if you are going there. When we were there a guy gave his card for a hostel which was very reasonable but I don't know where I have put it.

Dave