If you've used a shared hosting account and accessed it through cPanel or Plesk, the learning curve will be small. You'll have to do a few things to the server, but a decent hosting company will provide that checklist for you, or maybe even DO IT for you.
I've been using jaguarpc.com for my VPS for a couple of years now. Heard about them off either this forum or a webmaster forum. Very pleased. Always helpful, very reasonable pricing ($25/month). I was in the exact same position as you. It's a little scary at first because you don't want to blow anything up, but a good support team will walk you through it. You'll be very comfortable in a very short period of time. Good luck.