C++, Pascal will be of little help I'm afraid. Web developement can be broadly categoriesed into points as below, that you might want to learn.

Server side : PHP, JSP,ASP,Ruby. Presentation/Client side scripting : HTML,CSS,Javascript Backend: MySql, Oracle etc.

I suggest you to start a project and learn while you code, learning curve may be high for you depending on the level of exp you have.