Please read the seminal papers by Glendening et al. entitled Natural bond orbital methods and Natural resonance theory of chemical reactivity and come to class prepared to discuss them.
On the same topic, read chapter 3 in the book entitled The Chemical Bond.
Please also read the article by Krossing et al. entitled Dative Bonds in Main-Group Compounds: A Case for Fewer Arrows! and come to class prepared to discuss it. Note that this paper has created quite a stir!
Follow the impact of the Krossing paper to the present day by reading one or more recent papers that cite them. Come prepared to discuss the recent Krossing-citing work as well.