What are essential skill sets required to set up a website like myspace and other web 2.0 type website?

I want to offer a service over the net using a web site.

What are essential skill sets required to set up a website like myspace and other web 2.0 type website?
well, you need to know HTML (intermediat level) and CSS, eventually.





but most important, you must pay for hosting and subscribe to search engines (like Google)... oh, and lots of ads ;)