Free Assets for Artists

This is less of a tutorial and more of a compilation of useful links.
When working on a limited budget, it can be hard to find high quality, useful assets to use in your artwork.
Hopefully this list will make that search less painful for you.

Here is how I'm going to break everything down:
Site Name (link)
Permissions
Usefulness 

Images
Public-Domain-Photos
Free for Personal and Commercial use.
Large selection of high quality images.

CC Search
You can choose what sort of license you are looking for.
Allows you to search using many different pools of photos (for example flickr, google images, etc etc) for anything relating to your keywords and chosen license. Super helpful.

Fonts
Open Font Library
Unlimited use.
Limited selection.

Lost Type Co-op
Pay what you want for Personal use, Production use costs range.
Some truly great designs, but the lack of royalty-free fonts brings this one down.

Font Yukle
No Restrictions.
Great Selection!

Music
PD Info 
More of an information site on what songs are in public domain at the moment. 

MusOpen
No Copyright Restrictions.
Almost exclusively classical music.

Public Domain 4U
Free for Educational Use only.
Hits through history and forgotten classics.

Partners in Rhyme
Free to use but individual loops/tracks cannot be re-posted online for download or mixed into music.
Limited selection. 

ccMixter
Creative Commons
Large selection of music and loops that are community generated.

Free Soundtrack Music
Royalty Free with Attribution.
Large selection in a variety of styles, all oriented around the idea of fitting into a film soundtrack.

 Moby Gratis
Free license for filmmakers.
The musician Moby is offering a large selection of his music for free to filmmakers provided you fill out a form first that tells him exactly what your plans are for it.

Incompetech
Royalty free with attribution.
Hundreds of songs that vary in quality. Some are great, others are pretty rough.

Free Sound
A collection of free sound effects that range from Creative Commons to Royalty Free.
As it is community-driven, the site is always expanding.

Sound Bible
Ranging from Creative Commons, Royalty Free, and Public Domain.
Sound effects.

Stock Footage
Footage Island
Royalty Free stock footage.
A wide selection of varying quality with no real way to search through by keyword.

Stock Footage for Free
Royalty Free stock footage.
Tries to trick you into buying footage by making the first few search results links to a paid-footage site. Limited library.

Videvo
Royalty Free stock footage.
In order to download you have to share the video on social media, it's really annoying.

X Stock Video
Royalty Free stock footage.
Most of the footage must be paid for, but there is a small selection that is free.

Videezy
Creative Commons and Public Domain stock footage.
Expanding community of varying quality.

The Film Archives
Royalty Free collection of grain, flares, and light leaks.

The Open Video Project
Varies according to the clip.
A massive collection, from documentaries to government propaganda video.

HDRI Panoramics and Textures
Open Footage
Creative Commons
A great selection of panoramic photos