I'm curious as to what a (I assume North American) textbook looks like, is it something along the lines of the A Very Short Introduction series (in which case Miri Rubin's The Middle Ages: A Very Short Introduction, (Oxford, 2014), may suit the bill) or are they more in depth but still broad scope works? Do you have the ability to direct the syllabus and thus could engage with more nuanced topics (nobility, lordship, or lineage as examples) or do you have to cover a given period?

Medieval Europe: A Short History by Judith Bennett (taking over revisions from C. Warren Hollister) is perhaps not the book to make students fall in love with the Middle Ages. However, it is a solid chronological overview broken down by geographic region with social and cultural developments generally discussed separately. It's useful for a class that also runs on lecture and primary source reading components.

Although the book itself does not have an online component, Bennett also runs Medieval Europe Online, a very nice collection of bibliographies and topical links to online resources.