Start with a poem, rip open its seams and fill the wound with plot and dialogue, frames of reference. You now have a short story. Repeat the process and add popular culture - you have a novel.

To me, that is the truest writing process. It's like treating poetry as brainstorming, because it forces you to condense your thoughts into spurts of spontaneity and instinct.

Short stories are middle of the way but, in general, starting with something small lets you grow it into something more believable and relatable. So a short story is also a good launching point towards a novel, especially if poetry isn't your aptitude or you want a shorter journey to a finished product. Short stories are also good practice for withstanding longer stints of writing when working on a novel.

Short stories are between 1,000 and 15,000 words, though if you're hitting anything over 10,000 you're getting close to "short novel" territory. If you're writing between 400 and 600 words per a standard A4 page, 1,000 words comes to about two pages and 15,000 words comes to about 30 pages. A full-fledged novel is generally anything over 45,000 words (or, 90 A4 pages). Double the number of A4 pages to get an approximate book-size page count.

By the way, if you want to write a novel, you should check out NaNoWriMo. Each year, both experienced and inexperienced writers spend the month of November pumping out novels. The goal is to hit 50,000 words. It's a fun community and the local groups that meet across the world are a great source of inspiration.

The short story refers to a work of fiction that is usually written in prose, usually in narrative format. This format or medium tends to be more pointed than longer works of fiction, such as novellas (in the 20th and 21st century sense) and novels or books. Short story definitions based upon length differ somewhat even among professional writers, due somewhat in part to the fragmentation of the medium into genres. Since the short story format includes a wide range of genres and styles, the actual length is mitigated somewhere between the individual author's preference (or the story's actual needs in terms of creative trajectory or story arc) and the submission guidelines relevant to the story's actual market. Guidelines vary greatly among publishers.

Many short story writers define their work through a combination of creative, personal expression and artistic integrity. As a result, many attempt to resist categorization by genre as well as definition by numbers, finding such approaches limiting and counter-intuitive to artistic form and reasoning. As a result, definitions of the short story based upon length splinter even more when the writing process is taken into consideration.

I'd say a short is typically about 2,500 words. Anything less than 500 words is probably a short-short. (at least in certain genres). 10,000 and up is getting into Novella territory. That leaves a range between 2,500 and 10K, of course, but the 5k stories are usually the province of professional, well-known writers.

I'd definitely recommend learning the short-story form first. Novels don't require as much discipline, if you learn the short story first, you'll have more discipline as you move into the longer form.

Short stories typically range anywhere from 1,000 - 5,000 words. I personally believe short stories are a great place to start writing. Like djscram said, they teach you discipline and give you a way to learn how to be consice, which is something many writers forget to do when writing a novel.