Here are some handy, dandy (free) design resources:

Images & Photos

Burst
A free stock photo site that is powered by Shopify with 1000’s of high quality and royalty-free images available and free to download.

Creative Market
Register to download 6 free goods for a limited amount of time.

Pixabay
Discover the best source for free images and videos. Free for commercial use. No attribution required.

StockSnap.io
Hundreds of high resolution images added weekly. Free from copyright restrictions.

Unsplash
Beautiful, free photos. Gifted by the world’s most generous community of photographers.

Fonts

Creative Market
Register to download 6 free goods for a limited amount of time.

DaFont
Archive of freely downloadable fonts. Browse by alphabetical listing, by style, by author or by popularity.

Font Squirrel
Font Squirrel scours the internet for high quality, legitimately free fonts . Download thousands of completely legal, high quality, free fonts.

Illustration

Vecteezy
Choose from over 100000+ free vectors, clip art designs, icons, and illustrations created by artists worldwide! Download free art and templates for personal, educational, and commercial use.

Mock-Ups

Mockup World
An online service that offers designers and web developers free access to hundreds of ready to use mockups.

Audio

Youtube Audio Library
Browse and download free music and sound effects.

Other Image Resources

The Art Institute of Chicago
The Art Institute of Chicago revamped its website and released a searchable database of high-resolution art. Much of it is in the public domain – check the copyright notice on each artwork’s page. Only the public-domain art will include a full-resolution download link.

The British Library
Access a million stunning, copyright-free antique illustrations released by the British Library.

The Met
Access 375,000 beautiful, copyright-free images from New York’s Metropolitan Museum of Art.

NASA Image and Video Library
NASA Image and Video Library allows users to search, discover and download a treasure trove of more than 140,000 NASA images, videos and audio files from across the agency’s many missions in aeronautics, astrophysics, Earth science, human spaceflight, and more. Users now can embed content in their own sites and choose from multiple resolutions to download.

NASA Voyager posters & infographics
In celebration of Voyagers’ Interstellar voyage, posters and infographics are available for download, print, and share.