Always DIY - cheaper and so much more satisfying than following the lollipop......lots of sites out there will help you. Try google and cruise ports call boards - the first result.
It is really easy to do the excursions yourself we have done this cruise before. Maderia you dock right in the town get the water taxi across or we even walk it. You must go on the cable car the sight is just stunning and it cost about 18 euros worth every penny, when you have been there walk to Blandy's any one will tell you where it is sample all the maderia wine free. Agadir i would recommend a guided tour we went with thomsons we did not like this place at all you dock in the middle of a fish place. Arrecife in Lanzarote, walk out of the port and get a taxi very easy. Hope you enjoy.