The passage from the UK down to the Mediterranean does not need to be like an 'outward' bound course. The book is designed to help the lightly crewed boat, with perhaps only a couple of people on board, who are without much or indeed any 'offshore experience, have a relaxed and enjoyable time.
If you follow the route, suggested by the author, who has sailed to and from the Mediterranean, many times, in all sorts of boats, you will find it a very gently cruise, making landfall each afternoon in a relaxed fashion.
It details the ports, marinas and route you should use between the UK and Gibraltar. There are of course 'hundreds' of options but some are very much better than others and you need to know which should be your port or marina of choice. It is important to know if a port has 'must see' places to visit or has it got a launderette, good WiFi connections, places to eat at a reasonable price, if the broken 'widget' can be repaired there or easy flights back to the UK - it is also important to know the places you should avoid!
It is the cruise of a lifetime, occupying a summer or maybe two, so it does need planning. The book contain 'chartlets', pictures, port and marina guides. At home it will make it will enable you to plan and prepare for your voyage in a knowledgeable and sensible way.