Here are a few good sites that might work for you:
- http://www.pexels.com/
- https://pixabay.com/
- http://negativespace.co/
- http://deathtothestockphoto.com/
- http://picjumbo.com/
- http://startupstockphotos.com/
- http://isorepublic.com/
- https://stocksnap.io/
- https://unsplash.com/grid
- http://fancycrave.com/
- http://imcreator.com/free
- http://gratisography.com
- https://www.splitshire.com/
- https://www.stockvault.net/
- photopin.com
- http://startupstockphotos.com/
- http://www.everystockphoto.com/
- http://www.freedigitalphotos.net/
- http://www.photogen.com/
- http://www.rgbstock.com/
- http://getrefe.com/
Vectors