I used to teach several people basics of web-building. I dare to recommend you to study in three directions simultaneously or in the given order:
Get any tutorial on HTML and try to start writing simple pages in notepad. Later add here practicing of CSS.
Sample of tutorial: http://www.w3schools.com/html/
2. Programming PHP
If you are going to create anything more complex than static web-pages, you need to learn some language used for dynamic web-page generation (i.e. to produce complex HTML depending on some data without modifying it manually). Since PHP is one of most widely used - and at the same time it has very low "entering threshold" - i.e. it is easy to start - I recommend to get tutorial on it and start learning it too.
Sample of tutorial: http://www.w3schools.com/php/
3. Programming Basics, Logic, Data Structures, Algorithms
You probably very soon will found that though you have fair knowledge of language functions, you keep on failing to implement some tasks of processing simple data, searching etc. It will be time to practice on programming core itself. It is better to solve a good number of simple programming tasks. Find some decent problemset and proceed with it.
My web-site with beginner's programming problems: http://codeabbey.com
4. Database techniques
Data for websites are usually stored in databases, rather than in plain files. At some point you'll need to dive in this matter.
Sample tutorial: http://dev.mysql.com/doc/refman/5.0/en/tutorial.html
Sample tutorial: http://www.w3schools.com/js/
I think that at this point you will know well enough where to move further. It would be worth to learn some PHP frameworks (like CakePHP) or move to other languages (like Python or, perhaps, Java)