I'm not a VPS expert by any means but I'm fairly comfortable with managing my own at this point even though I still have shared accounts as they're for smaller sites where it's not justifiable to use a VPS. With that said, I'd recommend getting the cheapest VPS plan and mess around with it for a month or two using some test websites or low traffic sites so that you're comfortable and once you're ready, migrate your real sites on them to avoid headaches and downtime as a result of your experimentation.
