There are two types of marketing info you need. What strategies to use for real estate and how to effectively get the message across.
Books or courses on Wholesaling generally will have good ideas for strategies for real estate investing. For example
Mailing to non owner occupants
Vacant houses
code violations
foreclosure notices
bandit signs
we buy houses ads
Books on sales or marketing like the Dan Kennedy stuff will give you ideas of how to craft your message.
One book I read very early on that I thought was fantastic was "Investing in Real Estate" by Gary Eldred and Andrew McLean.
I haven't read it yet but another book that is highly recommended is "Millionaire Real Estate Investor" by Gary Keller.
You can also read my website in my signature below :wink: