How do I import third-party libraries for an Eclipse project?

Question

I’m trying to use two third-party libraries for a Java project in Eclipse: iText (to generate a PDF) and Javamail (to send this PDF by email), but I’m not able to or import them...

I’ve tried everything. I’ve already dragged the folder to the /src of my project, I’ve been through botão direito > Import..., I’ve been to the Properties of the project... I’ve done everything, but I’m not able to add the libraries to my CLASSPATH.

I’m having two main difficulties:

1) The libraries' folders are FULL of files, and I don’t understand anything. There’s a thousand .jar. I don’t know which one I need to play into the Eclipse.

2) When I play ALL files (either by Import..., whether playing the entire folder, some parts of libraries are imported, but others are not. For example: com.itextpdf.text yes, quiet, but com.itextpdf.text.Document no. Similar thing occurs with Javamail.

What I need?

From a REALLY GOOD tutorial, to someone WHO IS STARTING NOW... All I think skip many steps and I get lost. Most of them don’t even talk like they throw the library into the eclipse. And the others - who talk -, they talk like it’s the simplest thing in the world.

I’m going crazy anyway.

Thanks in advance.