I am searching for 3D artists for a 3D iPad game. Is there a good place in the net, where I could find one? He or she should have created game models before.
Depending on your budget, you could try contacting professional 3D artists at sites dedicated to 3D art. Two big ones are:
There's also a "Renderotica" for more naughty stuff, but I'm not going to link it here ...
A cheaper variant could be looking through modding sites for games for both art and artists. Two I can recommend are:
Finally, you can always look for nice objects at Google's 3D Warehouse and contacting the artists of the models you like.
You can also try GameDev.net. You can always find good freelance artists there looking for jobs.
I am working on an Android 2D game that uses 3D model animation frames for its animation (i.e. I'm not manipulating 3D models in real-time, just playing back previously captured frames).
I found a lot of my 3D models on TurboSquid.com, many of which were free and a handful I payed maybe $25 to $35 dollars for.
Depending on what kind of stuff you are looking for, there are a ton of free and low priced art already available.