Cal Evans has posted the second part of his series targeted towards clients contracting developers and how they can both get the most out of the relationship and work with them the best way possible (part one is here).

Look, if you could do this yourself, you would. The fact of the matter is there is just no such thing as "I *just* need a shopping cart." Do you have any idea how complex a shopping cart is? Even modules for things like Drupal, WordPress or Joomla require setup and proper configuration.

He suggests to the client that they don't assume the technology they might need (unless they know exactly what it is). Don't start things with "I need " - you're paying the developer for a reason. You are the one that knows the problem to be solved, let them worry about the technology.