Tea, Earl Grey, hot.

geep's method works, but try it this way, instead:

1. Go to Animation Setup in the Animation menu, and set the Duration to 0:0:0:1 (one frame only). Set the Frame width and height to the desired size of your rendered image. Click OK.

2. Arrange your scene.

3. Set your display mode to Cartoon-with-Line, Hidden-line, etc.

4. Select Make Movie from the Animation menu. Set Sequence Type to Image Files, Resolution to Full, and Quality to Current Display Settings. Enable antialiasing if you wish. Click OK.

5. Provide a filename and location for the rendered image, and select a file type (JPEG, BMP, TIFF, whatever).

That's all. This is how I do all of my line-art renders.