All the three types of case books are fine. But two caveats (both personal opinions) here:
- Case in Point is a good starting point if you know absolutely nothing about cases. However, the cases in there are pretty outdated and the quality is fairly low. I would not suggest using this book once you've done a couple cases.
- Quality of MBA consulting case books varies by school. Some can be the best resource for case prep, while others are not much better than Case in Point. You can tell by looking at things such as length of cases, presence of charts, quality of sample case solutions, etc.
As Vlad mentioned, these casebooks should serve only as a starting point. You won't be able to improve if you just read these casebooks by yourself. You will have to find someone, ideally with past casing experience, to case with.
In terms of additional resources, there are videos on youtube that teaches you how to do cases. Victor Cheng's website also offers some resources that a lot of people use. But again, the most important thing is to find a real person to case with.