quick note: check out plugins. Many for LiveReload, many for open in browser. check youtube for ways to write a command yourself. I am looking for something that actually gives a preview IN Sublime, but I don't think it exists. Need to open in the browser to keep up with latest browsers...
I've been using codekit for live preview and preprocessing now. It does all the magic things. Sublime and codekit are a superforce of productivity!
I second what sheriffderek said, CodeKit is excellent for this specially if you sue LESS/SASS. It will update your browser window on save and does it with a nice smooth animation to reflect the changes as opposed to a complete refresh fo the browser window.
Customer support service by UserEcho