Whether art board, paper, or canvas, there are places you can skimp and places you cannot. Better to buy masonite panels at your hardware store and gesso them yourself, then buy a badly stretched, flimsy canvas at a big-box craft store. Better to save up and get paper with a good tooth rather than get cheap stuff that will make it impossible to get a good line. That said, a ream of printer paper is good for most marker or technical pen practice. It does have a tendency to bleed however.
For the novice, better paper tends to tell you what the weight is. The simplest rule is, generally, the heavier the better.
For interested parties, some of the best deals on quality art materials can be found at DickBlick.com.
Mindflight 