Pro teams do tend to train there because of the climate. I had a friend who did some road riding there a while back and she really liked it. But it doesn't seem like that large of a place. Only 1,400 sq. miles. How long are you planning to tour?
Back in '00 I spent 7 weeks cycling around Andalucia. I planned my trip using the "Rough Guide to Andalucia." There is one for Majorca:
http://www.roughguides.com/website/s...a-Menorca.aspx
I highly recommend this series. They are usually incredibly detailed. More importantly, they do not pull any punches when it comes to evaluating accommodations, restaurants, sites, etc. If something sucks in their opinion, they will tell you that it sucks.