Hi,
Coyle is one company that does the kinds of mystery shops you are looking for. They expect high standards from their shoppers. They are not going to hand you a cruise right off the bat but they do have telephone, hotel, restaurant shops as well.
I would recommend sigining up with them and doing some of their telephone shops to get started.
There are some posts about Coyle in the 'Mystery Shopping Company Discussion' section. A link to this section can be found at the bottom of this page on the left hand side.
Happy Shopping and welcome.