Sketch Sheets offers free downloadable templates for various devices; a great tool for UI/UX designers.
FREE TREES & PEOPLE
Luis Bertomeu has put together a bunch of free trees and even people for download.
ArchiSoup has compiled the top 9 free websites for cut out png people!
Quickly and easily download and print digital paper, available in both PDF and JPEG Formats.
The biggest collection of official brand color codes around.
Archweb has a number of free .dwg files to help give detail to your drawings.