This library contains a list of some of the artistic reference sites I frequent while working on various projects. Each of these services are free and highly intuitive. Hopefully these will be as valuable to you as they have been so far for me.
A free resource for stock photos online that can be used for different applications and disciplines. I have used this site a few times to get inspiration or start my inevitably large reference libraries for various projects.
A fairly extensive database containing line-art of different objects in profile. Excellent for modeling and silhouette reference as well as a start for understanding form and function of everyday objects.
While there is an option to purchase the actual models for your own use, I typically use this site to compare my own models to industry-level work. I also visit this site when I cannot find reference material for a specific project.
A small collection of networking sites related to 3-D modeling and animation and the video game industry. Not all networking sites are for everyone, but they can at least serve as a haven for inspiration and motivation.
CG Society is a hub for some of the world's most talented 3-D modelers, 2-D concept artists, and animators. You do not need a subscription to view some of the latest released projects and to read up on those still in development.
Gamasutra is a great site to visit to gain access to industry news, developer post-mortems, and more. It's a good site to become a member of, if at the very least to subscribe to their email list to get frequent industry updates.
Modding is a very viable facet of the gaming industry, and should never be overlooked. Incredible independent talents can create entirely new experiences from the core of existing games. This site is good to view some of the latest mods in-development.
Unity is another free-access engine that gives independent developers the opportunity to experiment and develop using industry-standard techniques. These tutorials start with the basics and work up to more advanced techniques to answer any questions that could surface.
The official archive provided by Unreal to help independent developers learn more about the free game development kit. These video tutorials cover a wide variety of topics and are a good starting point for answering any question that might come up while working with the program.