I would like to make my dev sites have port numbers. I thought I would just start at a certain number and increment by 1 every new site. The question is what number should I start with? I have know there are reserved ports at various numbers. Are there a range of numbers that can be assumed safe to use?
Wikipedia has an exhaustive list of well-known ports. You should probably pick something 1024 or greater that isn't already in use.
user983223 you can use ports bigger then 1024. Using virtual hosts is a better approach to building a good web development server. If you need more information on setting up virtual hosts let me know your OS and web server details, that way I will be able to help you.