A book suggested to me by my therapist. It's a Dutch one so probably useless to you.

> Is there anything you wish you knew when you had just started getting into mindfulness?

I wish it was made more clear to me that this is an evidence-based method with plenty of scientific support for its effectiveness, so I would have been less sceptical and picked it up sooner! My therapist was kind of... let's just say that his master thesis was on astrology.