This isn't a very strong recommendation. There is interesting and useful content, but presented in a way that can be viewed as eccentric and almost none of it I believe is best read from here. I don't view the insights the Tolle has had as being original.
We live our lives in the fantasy of the past and future, but we tend to neglect the reality that is the present.
Can you drop the narrative of your life and pay attention to what's right in front of you, even for an instant? It seems to me that living a happy and fulfilled life, is entirely dependent on your ability to do so.
It's a message that's been echoed by spiritual teachers throughout the ages, but in a well received popular format.
Alternatively, if you do not understand much about this notion of a spiritual life and would like to understand more, I recommend you give a read of the much less grandiose Waking Up by Sam Harris.