VPS Web hosting is a middle-ground between shared and dedicated Web hosting. It offers you the ability to share a server with several other customers, while still allowing you the room and flexibility of a dedicated server. What happens in the main server is split into smaller, virtual "servers". In the end you get all of the independence and flexibility that comes with a dedicated server, without the larger price tag.
When shopping around for a good VPS host, it is a good idea to keep your eye open for a certain number of deal makers. You may find some of these items more useful than others. This list is some of the most important perks to be looking for in a prospective VPS host. Good luck, and happy hunting!
What hardware are they running?
The most important thing you want to check on is the hardware the host is using. You want to be sure they are running dual CPU, quad core Xeon processors. Also check to see that they are using hardware based RAID on their drives. They should have at least RAID 5, but RAID 10 is better due to it's speed and stability.
Check the software
If you do not have your own operating system preference, it's tough to beat CentOS 4 or 5. Each VPS should, of course, also come with root access that is unrestricted, giving you administrative access to your website and the server which it is hosted on. You also want to verify that you can host as many domains as you think you may need. Also check that they offer the control panel that you like working with. If they are not, research what the alternative is, because cPanel is fairly common, and also one of the best. You also want to make sure your VPS comes with at least 2 IPs. You will need 2 IPs to setup name-servers on your domain.
You also want to be very careful if you choose to pay in advance for hosting services. Even if they offer a better deal, you never know what changes a month will bring. You should always look to pay monthly so you can leave when you need to.