If you are new to Drupal or need a little extra help with getting over some of the initial hurdles, we selected a number of resource that were reviewed and discussed at our last Oxford Drupal Users Group.
Diving in and getting started with Drupal is ideal. Running a Drupal project requires a large amount of Drupal knowledge to design and scope the website in advance of building it, so that your development team are able to work efficiently to a carefully considered system architecture.
The following books help understand the best way to approach Drupal development projects based upon its framework and intended design.
Programmer's Guide to Drupal (Principles, Practices, and Pitfalls)
By Jennifer Hodgdon
Pro Drupal 7 Development 3rd Edition (Expert's Voice in Open Source
This is a selection of video's produced by Lullabot that provide an extensive range training videos from the basic right through to more complex elements of using Drupal. There are many free videos available.