A long time ago I stumbled upon this site when googling various things like How to become a Prison officer etc.

Ok the inside information is not free but believe me you do get you monies worth.

Give it a try:

http://www.how2become.co.uk/index.php

I recently attended a one day course on How to become a paramedic and was pleasently surprised at the mass of info I was given.

They have a whole host of packs on many careers so take a look.