Discuss the balance between design and site performance. A good design will take into account these issues, and if the design is executed properly, there should be few problems for the intended end user. The Web is opening up many more jobs for artists and designers and schools are offering more classes that deal with digital imaging and design. It seems as though the Web is responsible for giving the design profession a boost in popularity. There are many considerations when designing for the Web, probably too many to go into any great detail.
All mediums are different, and so design criteria are different.
Concentrate on becoming a great designer first. Everything that you do should be about design. I usually don't care if they know HTML, CGI, and Java Script. I have a technical guy who does all of that anyway. There is a completely different set of tools available to a digital designer, and those tools May have a great impact on a designer's work.