For those looking for hosting and for those enticed by the cheap plans offered by companies like Dreamhost, I recommend you take 5-10 minutes and read these two articles.
If you were running a brick and mortar business, your website would be like your storefront. You wouldn't try to save a few bucks by building your storefront with scrap metal in a seedy part of town, because you'd end up losing customers. Why would you do something similar with your website?
http://whreviews.com/overselling-hosting.htm
http://whreviews.com/shared-hosting-res.htm