You can easily get programmers to work for free if you offer them a good idea. But artists, believe me, they are harder to convince. And they are in short, go to the jobs section of some of the major game development studios and you will see that usually they are looking for 2 or 3 more artists.

For beginners, it is difficult to find an full-time artist, so what can you do to satisfy your content needs if you are not a jack of all trades? Well, there are some sites that can provide you some art assets. Even when they don't exactly fit, at least you can use them as placeholders. It is better something than nothing!

Turbosquid: They have a large repository of 3D models in several formats. Some of them can be freely download.

Blender open model repository: Has a few royalty free models (around 400) made with Blender.

Blender texture CD: Previously for sale and now freely downloadable, this set of textures and materials can help you a bit when doing basic work.

Free Game Arts: Free Game Arts promotes the use and development of free and "open source" game resources, including 3D models, sound effects, textures, games and development tools.

OpenGameArt Open Game Art is a community that brings like-minded coders and artists together for the purpose of creating Open Source video games, by providing a human-edited, searchable database of freely-licened art resources.

This list is far from being complete, obviously, and I will try to expand it as possible in the future. Also, if you have some link that is not included here, please feel free to suggest it.