This varies depending on what your need is. For most personal and low level business sites you will simply need a Linode 360 account which costs $19.95/month. If you begin hosting many sites and you get a lot of traffic you will need to upgrade like I did to a Linode 540 (at $29.95) or even higher account. I would recommend starting at the lower one and upgrading down the road unless you know for sure that you will need something bigger.