Best option: Brand Photography
If the client has brand photography, you can find it on the OfficeDrive here:
Shared_Office_Files2 > Clients > [Client Name] > Photos
Second option: iStock
We have an iStock account for stock imagery. You can only use this option if you have a seat (we have three, two are used by full-timers, one is for the most photo-hungry intern). The person who uses the seat is the only person who can use the photo in creative.
Third option: Creative Commons
There are several good places we use for Creative Commons photography, but use caution: sometimes a user will steal a copyrighted photo and upload it as “Creative Commons”. Always be sure to credit the source unless the site says specifically you don’t have to.