Common job titles/roles and requisite skills in the web

Graphic designer/Web designer/Designer
Builds a visual interface – an image
Skills
Adobe PhotoShop
Adobe Illustrator
Art / color / design
User interface knowledge

Web developer
Usually converts the comp or image into XHTML/HTML/CSS
Skills
XHTML
HTML
CSS
Able to prepare images for the web
Able to use javascript to support rich interfaces

Internet/LAMP engineer
Usually makes the site work – provides all backend support to get the HTML from the server to the browser
Skills
HTML/CSS – basic competence
LAMP – understanding of the whole stack
Strong logic
Able to install a commercial application and make it run
Able to help a developer customize an application

DBA
No explanation needed

Content Editor
Responsible for posting content
Skills
Strong written communication
Should be able to associate images with text
Able to connect content with links, reusing it efficiently

SEO
Responsible for setting up a site to get the best possible search engine positioning
Skills
Able to follow the instructions at Google/Yahoo, etc
Should be able to handle basic Linux commands
Advise content editor

Server admin
No further explanation needed

Site admin
Handles issues like setting up email accounts, supporting clients