Here's my take on it.. I was fortunate to find the right material when I started prepping. And I figured out DP in a relatively lesser time. I wont say I can solve any DP question but I can solve most of the DP medium questions and a few hard ones.
Understanding Recursion is the core to it.. By understanding, what i mean is, 'You don't debug what is happening inside recursion. You dont build the recursive stack. You simply write the base case and call the sub problem'
Try solving a lot of problems on Recursion.
Once you understand Recursion, you'll able to write backtracking easily.
After solving some questions on Recursion, head over to DP. DP ; the top down part is Recursion where you memo certain parts. This is more of a process.
Up until Recursion isnt clear/intuitive to you, you would never figure out an intuitive way to solve DP.
Links: Watch the videos as they give you the basics for Recursion, Backtracking. Read the Textbook simultaneously. All of this will make your fundamentals really powerful. Many things will start making sense.
http://read.pudn.com/downloads516/ebook/2141173/CS106BX-Reader.pdf - This link is used by the Stanford students in their CSE101 course and the chapters 7,8,9 are very interesting and easy to read.