The Ordnance Survey blog posted a nice small compilation of cartographic resources today. They add some more colour resources over the ones I have already reviewed, as well as sites on fonts, symbols and “inspiration” (can’t all of us use some of the latter from time to time? ;-).
Definitely not all of the listed resources are brand new, but I have found at least two interesting things I haven’t known: Maki Icons by MapBox or ColourLovers. Also not in the “new” section, but definitely worth checking out if you are not yet familiar with it is The Noun Project.
Let me know if any of it sparks your creativity!