HTML is the basic structure all of web sites. I begin with it and I have studied it many times. First the 4.1 version and then I learnt the new features about HTML5. It is simple and easy to understand, even though there are some tricks not very intuitive for normal users.
CSS is the perfect complement of HTML because it styles the void text written in web pages. Color, background, font, position, margin, … there are so many possibilities you can play with it.
JQueryUI (JQuery User Interface) is the fastest way to build complex widgets easily. For example, menus, buttons, progressbar, datepicker, spins and so on. Is almost so important as JQuery.
When I began with this tecnology was very popular web application framework for Java EE projects. It is a stable and consolidate way to make web apps, however it is very complicated to learn how it works.
Express is a web framework for node. It is almost imperative if you use node because express gives you a lot of facilities.
After studying relational databases like MySQL I thought I had seen it all about databases. How wrong I was! I found mongoDB and I liked its model a lot. mongoDB is a NoSql and JSON-like paradigm.