I like reading books that deal with marketing philosophies.
Check out
Growth Hacker Marketing - Ryan Holiday.
- Book showing real world example of blackhat tactics, and results. Otherwise noted as "Growth Hacking"
B2B Digital Marketing - Michael Miller
- A little old, but has some good references. General B2B Internet Marketing
Generally stuff you may already know, Although the professional prospective and real world results of what "Blackhat" can do to a business, is what I believe is of value.