I bought this book and it seems very comprehensive! You can get all the info online from the following link
www.FabJob.com/florist.asp?
It includes chapters on:
Preparing for Your Florist Career
How to Get Hired as a Florist or Floral Designer
How to Start a Flower Shop
There's a digital version or hard copy with Cd (mine arrived today) - am really looking forward to getting stuck into it. Its from the U.S. so some of the info may not be entirely relevant to us here in the UK but overall i think it is worth a look at.