First bit of advice: usability test the designs, but we all knew that, right?!
Second bit of advice: make sure you find out exactly what drives the department, and nail the display of those KPIs and metrics.
Resources & Preparation
The must read book in this area is Stephen Few's "Information Dashboard Design". It's a goldmine of information, and how-tos, and how-not-tos. Also read Tufte's Beautiful Evidence, as it explores sparklines in great detail.
I would know your technology too. Are you building from scratch, or using a tool (a horrible, horrible tool...) like Xcelcuis? If it is the former, then great, there are loads of fantastic tools like jQuery Sparklines that you can easily leverage. If it is the latter, then know the limitations and prepare for frustrations.
Another useful addition is Color Oracle, which works brilliantly on a Mac (can't comment for the Windows version). It simulates colour blindness on screen, and saves you exporting images elsewhere. It also forces you to rely less heavily on colour, and add in extra stimuli for RAG states.
One final tip: design & preview on the screen/projector the final output will be displayed upon. It can be quite a shock when you transfer from a high quality desktop/laptop screen to a projector/TV screen, as colour disappears and things that looked great turn mushy.