I bought this book after switching university course and not being sure what I was going to do long term. Overall, it is exactly what it says on the cover an 'A to Z', not an in depth analysis of every possible career out there. However, it does give the broad picture for hundreds of different career fields and suggests similar areas of interest. I think it would be impossible to go into minute detail about every available profession and this book gets the balance right.
Easy reading, you can dip in and out for ideas and then go on to do a bit of further research if you find something interesting. Would recommend for school leavers and university students but perhaps not for those further along in there career.