Hello Qt Center !

I am kind of new to Qt but I manage to program a nice application with lots of classes subclassing QGraphicalsItems' children.

Now I want to use thoses classes in another project.
I would prefer not having to copy/paste everything and start typing all those path into que ".pro" again.

As a newbie, what would you recommend to store my classes to be reusable later ? (note that I might want to do some changes again on those classes, as my program keep evolving...)

I have hear about libraries, so that i could have some dll's ?
I also read that some people are using templates ?
I was thinking about storing all my classes into a new Qt project, but then I am not really sure how to reuse it...

Regards,
Max