Building a website incoporates a variety of software, talents and skills. We have been developing websites since 1995...and yes, a lot has change over the years.
In order to develop a website, here are some of the basic/advance skills we use:
1) Graphics skills and software to create the design for your site, to edit images and size them correctly for the website
2) Some HTML and PHP code authoring tools and skills
3) FTP - Once we develop a website on our PC/MAC, we need to transfer it to our webserver to make it available to the world
4) Browser debugging tools are also helpful.
5) Database knowledge - this is critical since the way we build websites these days is to store all of our content as fields in a database. This makes the presentation have unlimited options.
6) A webhost...this is the physical webserver that the files for the website reside on