New to touring abroad

nicbecboz

Hi all. We have booked our ferry Dover to Dunkerque on 3/6/14 for a month in France for our first trip abroad. We have a couple of worries/questions, what is the talk about reverse polarity? I think our van a 2012 Swift has a button on the control unit -
what does that do?  We are going to use  sites in the Alan Rodgers book along with their map so we can plot a route, any suggestions where we can go for the month?  Any general tips for us 2 newbies to taking the van abroad would be most welcome.