A book called "Change Your Mind: A practical guide to Buddhist meditation" was very good for me. It's written by an English Buddhist monk, but is singularly free of any mystical or religious content.

I had done a course called, 'sahaj samadhi' (loose translation in english: calm meditation) from Art of Living foundation. I found it very easy to follow.

Also sometimes, I do guided meditations.

I just started. Sit comfortably, breathe fully, notice your breath or your pulse and just relax. Sometimes I try to keep my mind clear of thoughts, sometimes not.