I'm a teacher and I've written several grammar workbooks for my students, meaning 8.5x11 books in which they circle and underline things and write answers in words. I'm in the process of publishing my books as paperback on Lulu, and I want to do an electronic version for ipad because my school is transitioning to ipads for students. I'm new with ipads, so I'm wondering how I can create an ebook of my workbooks that my students can buy for ipad and in which they can write their answers (either with stylus or keyboard). I've seen students take iwork documents and fill in worksheets with them (for example, when they need to write some words in boxes on a graphic organizer), but I want a format that I can sell with DRM. If I sold them a pdf via Lulu ebooks, would they be able to annotate it in a way that was like writing in a physical workbook? thanks for any advice.