Before you start creating websites you should master HTML. This is the key element to even start publishing documents on the web. This sounds pretty obvious but there are some elements that you should understand like the label element which will add great usability to a form.
2. Master Cascading Style Sheets (CSS)
I can't stress this enough. DO NOT USE TABLES FOR YOUR LAYOUT!
Is it clear? Don't, just don't. Why? Because they work against you instead of for you. You can have so much more control of your layout, design and colors if you use 100% CSS.
1. CSS is easy
2. CSS is fast to create
3. CSS is lightning fast when your website loads
4. CSS is easy to modify
So forget table layouts and start using stylesheets. You will really like the things you can accomplish once you master them.
3. Learn A Server Side Language
This is needed to make dynamic websites like forums. PHP and ASP are a great example. You will need to understand what you can do with these languages and start using them.
Without a server side language your websites are really hard to maintain and will give you a hard job in creating an efficient website structure.
4. Learn A Database Language
I recommend learning MySQL since this is an open source database and is installed on most hosting providers in combination with PHP.
A database is nothing else then some tables with data. You can select data with queries like:
SELECT * FROM table WHERE ID = 3;
Now everything is selected from table when the ID equals three. It's not hard to understand SQL, you just need to know how it works. PHPMyAdmin can help you a lot when you are creating your database.
So, start with step 1, and stick with CSS as long as you don't master it. CSS is huge, and you will love it once you know how it works.
For application development you can't do without a language like PHP and a database like MySQL.
