Q. What is the average length of a novella? And is it'pitched' to literary agents the same way novels are 'pitched'?
A. Novellas generally run 20,000-50,000 words. About 30,000 words is average. While this number of words would be very common when pitching a nonfiction text, such a length reminds me of tennis lessons in my youth. My coach would tell me to stand at the back line to volley or approach the net, but never to float in between the areas, because that was "no man's land."
That's what a novella feels like to me: "no man's land." Very much too long to be a short story, and very much too short to be a novel.
Concerning how to pitch it, Gene, my first advice is to expand it into a novel-length work (at least 80,000 words). If that's not a possibility, then you can simply look for the few agents out there who do represent things such as novellas and short story collections, then try them. You would query the same way and the work needs to be finished and polished before you do. The odds of success here are very, very small. My best candid advice is to finish this novella and stick it in a drawer. Then write a few novels, get them published, and gather a moderately loyal readership. When you do, a publisher will release your novella in a small print run and your loyal readers will gobble it up. Everyone wins.