Conditional Formatting - highlight overdue dates

I am a beginner with conditional formatting and researching the net for an answer has left me more confused than when I began!

I am working with Excel 2007.

I have list of 'next inspection dates' in a column of which the cell values result from a formula based on a date in an adjacent column (last inspection completed) + a specific number of days to determine when the next inspection is due.

I need to format the next inspection date cells to highlight the next inspection dates that are now overdue ie: dates prior to today's date.

Some of these cells have text 'TBC' as the adjacent cells dates are 'Pending'. The TBC cells must also be subject to the formatting for when the Pending status changes to an actual date.

Your assistance is appreciated.