Keep in mind that "web design" includes all areas of designing a website including graphics, layout, and user experience design - which can also venture into bits of coding.

Web development, on the other hand, USUALLY (not always) refers to the main non-design aspects of building web sites: writing markup and programming.

http://en.wikipedia.org/wiki/Web_design
http://en.wikipedia.org/wiki/Web_development

While they can be used interchangeably, there is also an added layer of uncertainty as to what you're talking about when doing so.

Anyway, as with everything else, it does take time to learn and it can be a big learning curve if you've never dealt with it before. For starters, I'd focus my time on one area and get to a comfortable level with that. Rather it be working with graphics in Photoshop, Illustrator, or GIMP or learning the basics of xhtml/css2 and then venturing into html5/css3.

Either way, I find all areas of it to be a lot of fun and challenging and a great way to exercise your creative mind!