Hi Jonathan,
Under File > Document setup > Paper, at the bottom there is the rendering setting. Leave "Edit quality" something lower or medium (for better performance) and set Output quality to high.
When exporting to raster, High will be 300 dpi, medium 150 dpi and low 96 dpi (I think).
Raster output is what it says; a simple image output. Vector is vector based but will not export textures just as colours. Hybrid will export edges as vector an textures as raster images.