Field studies show that in many learning settings paper has intrinsic advantages over electronic documents. In this paper we present concepts for the collaborative annotation and structuring of paper documents and digital documents in both distributed and co-located settings. The CoScribe prototype supports the annotation of printed lecture slides and collaborative sharing of annotations. Digital Paper Bookmarks and tag buttons are means for the efficient semantic structuring, indexing and tagging of paper documents. We then detail on results of an ethnographic study on learning group meetings. These demonstrate that printed and digital documents form one document space and that personal interactions go in hand with manipulating documents. Based on these findings we present the design of a prototype which supports efficient annotation and structuring in co-located learning group meetings.