As solaris said, there's a lot of areas in web development, and firstly it's worth noting that a web developer !== web designer.
I work as a developer in a design studio, so a lot of my stuff is short, lightweight projects which are over and done in 2-3 weeks, although there's the odd grinder which goes on for 6-9 months on and off.
I personally work with:
Classic ASP
ASP.Net C#
MSSQL
JavaScript & jQuery
XHTML
ActionScript (Flash)
It would probably also help if at least you know your way around photoshop as more often that not you'll be given a PSD to build the site from.
*edit*
I've just noticed you're in MK - shame you didn't post this a couple of months back as we had a job going!