Bookmark and highlight PDFs

I have some rather large PDFs that I have imported in my project, and I was wondering if there was any way of adding notes and bookmarks to specific pages. And if not, what approaches are people using instead?

Thanks, Rob

This may help: http://skim-app.sourceforge.net

Thanks, I had a look, but I think that what I really would like would be to able to select some text, add a comment, and have it appear under the “Comments & Footnotes” section. I suppose I could write something in the Document notes, but it would be nice to be to jump to page 20 in a PDF that I have imported.