Creating markers in plug-in

[kaprasanna]

I am new to eclipse plug-in development.
What I want to achieve is this :
If the user clicks on a button inside a view, a particular line in a particular java file
should get highlighted and a error-like mark should appear next to it.
Also, if the user hovers his mouse icon, he'd be able to see a yellow sticky box with a message.

After searching the net, I can say there is no document that gives me the basic steps I should be taking in order to achieve what I want to. The template available in eclipse new project wizard creates all extensions and classes but no clear documentation is present that tells me where I go from there.
I came to know there is a plug-in org.eclipse.core.resources.marker.
But I don't know how do I use it.
Also there is an interface IMarker. But the java doc says, "This interface is not intended to be implemented by developers".

Probably this is simple but with no proper documentation I am not able to pull this off. Please tell me how do I proceed?

Thanks in advance.