Keys (replace Command with Ctrl on non-Mac machines):
Command-1: No splitsCommand-2: Two vertical splits, press repeatedly to switch between 50%/50%, 33/66% and 66%/33%Command-3: Three vertical splitsCommand-P: Two vertical splits where the right previews the one at the left (supported for some languages, e.g. Markdown, HTML and CoffeeScript)Command-Shift-1: Move currently focused split to window position 1Command-Shift-2: Move currently focused split to window position 2Command-Shift-3: Move currently focused split to window position 3