If you choose the Texture Type Image in the Texture Panel, the Map Image and Image panels appear, allowing you to control most aspects of image textures and how they are applied.
We know that around the world, our users have PC's of widely varying power. Rendering is the process in CG that can chew up CPU and disk space like no tomorrow. Especially in corporate environments, it is easy to fill up terabyte servers by uploading ten hour-long DV tapes and doing some editing. So, there are lots of options try to shoehorn a big job into a small PC by providing you with multiple sets of options that chunk up the work as best we can, while still preserving image integrity.
This page discusses the main options found on the Render panel, and subsequent pages give you more.