I know it can be super overwhelming, but the DAT sub-board on this site is pretty useful. Honestly, what I did was just use the Kaplan blue book plus a few MCAT subject books (bio, chem, and orgo) that I checked out of the library! (they didn't have any DAT books, sadly so I just used what was available). The Kaplan is good for review, but I would't use it for subjects that you actually need to re-learn. Whenever I totally didn't remember a concept (usually with orgo) and the Kaplan/MCAT books weren't helpful, I just went back to my old textbooks and orgo notes. I also found as many practice tests as I could (a friend of mine had some different DAT study materials than me and so she lent me some of the practice exams that were in her books)-- those were super, super helpful!
For the PAT section I used the Crack PAT. Although it can be a little pricey, it's totally worth it. It's great review!
I didn't bother with any of the online videos or any of that, but honestly it really depends on how you study best and how much supplemental material you need.
Good luck!