There are websites, services which offer great resources for graphic designers .

We can suggest some websites :

officialpsds.com – PSD files
photoshop-kopona.com – PSD files, stock images
freepsdfiles.net – PSD files
freepik.com/free-psd – PSD files, stock, other
psdbox.com – resources
resources.psdbox.com – resources
photoshopfiles.com – PSD files
raumrot.com – stock images
freeforcommercialuse.net – stock images
unsplash.com – stock images
isorepublic.com – stock images
imcreator.com/free – stock images and resources

Image Hosting
For full control over your media (images) content we strongly suggest using your own host or an adult-friendly image-hosting service.

We DO NOT recommend using Photobucket, Imgur or similar services for obvious reasons