Worldbuilding: Part 1

Geography

How do you create a Fantasy World?

One of two ways: either you start from scratch and create an imaginary world (an example: The Wizard of Earthsea )or build fantasy into our real world (an example: The Dresden Files).

Starting from scratch:

The first thing you do when building your world from scratch is decide what you want your world to look like. Is it going to have continents, are you going to just concentrate on one region only, is it going to be a world of water and islands, perhaps it is under the sea, or a desert world. Whatever you decide, you must know what the basic geography is like. I suggest you draw some maps; they don't have to be perfect, just a guideline to help you out. In creating the world of my novel-in-progress, Song of the Wind and Sea, I drew two maps: one topographical, with the geographic regions labelled (I colour-coded the geography) and one listing all my kingdoms, and their cities and towns. (If you need help with creating geography do some research into topography, and look at different types of maps.)
Once you know the basic geography, fill in some details; creating an outline can be helpful. Now you need not be too detailed at this point, just know where your mountains are, your forests, whether your main city is built on a hill, are there dangerous animals lurking in your regions, are there rivers that your characters will have to deal with, etc. More details will most likely emerge as you write, so if you start with maps and a reference outline, it is easier to keep things straight.