These tasks and knowledge usually come before any graphic design apply into a website, this will turn and push a website getting more value and understanding as usable.
Core Skillsresearch techniques
ethnography and discovery—user goals, motivations, and work patterns
user modeling—persona and scenario creation; role-playing
product design—product-level interaction principles and concepts
interaction design—function-level interaction principles and concepts
interface design—component-level interaction principles and concepts
information architecture and information design—content structure and presentation principlesUsability Skillsknowledge of usability testing principles and methods
knowledge of principles of cognitive psychologyMedia Skillsunderstanding of bit-depth, pixel-density, and resolution issues
managing color palettes
icon design and pixel-level design
graphic user interface (GUI) screen layout and composition
page layout and composition
animation
sound design
prototyping—paper, Visual Basic, HTML/CSS, Director, Flash, or other methods
knowledge of file formats and tradeoffs
Source
The Skills of UX ProfessionalsBy Robert Reimann
A UX designer has to have all the skills of any designer, but also needs to focus on people the users not just on business goals, skills, or techniques.”—Whitney Quesenbery