Why are we even having this conversation again?

Traditional Catholics' ignorance of Scripture is legendary. Why not start with that -- read the entire Bible through from cover to cover at least once.

Read the Gospels themselves many times, until you know what's there (and what isn't). Unlike the protestants, we don't need to memorize where each passage came from. You can always look it up later on DRBO.org. But even DRBO won't help you if you don't know what you're looking for! So you need to familiarize yourself with what's in Scripture -- in doing so, you also learn what ISN'T in there, which is equally useful.

Then, read a concordance or Life of Christ based on Scripture. I learned a lot from one of these. I'm trying to remember the author. It's basically all 4 Gospels put together, with Catholic commentary and historical details to really flesh it out.

And once you have that foundation, then it's time for some approved private revelation if you have time.

The Life of Mary as Seen by the Mystics, written by 4 approved Catholic mystics, would be a good start. And then Venerable/Blessed/Saint (take your pick) Anne Catherine Emmerich wrote a 4-volume Life of Christ and Biblical Revelations. The 3rd volume of this series is better known as "The Dolorous Passion of Our Lord Jesus Christ". Mystical City of God comes to mind as well.

That is PLENTY of reading material there, just restricting yourself to non-controversial, solid, Church-approved visionaries.

If you are done with all of that -- then I suppose cracking open "Poem of the Man God" wouldn't do you much harm -- because anything erroneous or bad in the work would be recognized and repugnant to you, clashing with everything you've read up till now. You will likely end up putting the book down on your own.

But for those who haven't even read the Bible yet? It's vain curiosity, sentimentality, and imprudence talking. DON'T DO IT!

P.S.
And no, you don't have to turn in your "support +Williamson" card if you choose to reject his advice on this matter. Don't throw out the baby with the bathwater. I am one of +W's greatest supporters, but I recognize that no one is perfect and in the scheme of things, this isn't that big of a deal.

Incidentally, he can't really blame me for disagreeing with him on this; I have some pretty good reasons (above) and at least I'm thinking for myself. That's what he taught us to do.

Very good advice. This is the counsel which our clerics should be promoting and giving to the faithful, but alas.............

I've been doing spiritual reading for the past 53 years.  I've read Emmerich's Life of Christ and Agreda's Mystical City of God.  I assure you, The Poem comes nowhere close to these masterpieces.  These two "Lifes" will inspire you to pray, increase your love and devotion for Our Lord and Our Lady.  The Poem does otherwise.  It downplays both of Them, putting Them on a too-human level in a disgusting manner.

I tried to read some of it about a year ago because +Williamson recommended it.  I found it utterly disgusting and after three tries had to put it down for good.  Jesus does indeed sound like a ɧoɱosɛҳųαƖ and Our Lady sounds like an emotional woman who is ignorant and subject to the effects of sin by some of the actions attributed to Her and things She allegedly did.  What I mean by this is that She reacts to circuмstances not with perfect humility and obedience to the perceived Will of God but rather as someone who finds it difficult to control her emotions--an effect of sin.  

For anyone familiar with the books already (if you haven't read the Poem, don't!), compare Her reaction after Christ's death in Agreda and then in the Poem.  In the first She is dignified, suffering immensely but in control of Herself and is a great model for us.  In the Poem, She is like perhaps any of us--needs to be restrained in Her grief, etc.--human frailty--the result of the taint of sin.

If you read enough of the two and make a comparison, you will see two very different types of women portrayed as Our Lady and Agreda's account will lift your spirits and enlighten you and increase your devotion to Our Lady.  Valtorta's portrayal will make Her seem like the rest of us or worse, leaving you with no inclination to pray to Her because She seems no different than you or I so why bother?  Her dignity as Mother of God is downplayed as is Jesus's as the Son of God. Horvat's assessment is spot on.

It's helpful to meditate on the life of Our Lord and Our Lady, especially while saying the Rosary.  A good "Life" comes in very handy and many saints have  recommended such books.  But please--stay away from Valtorta!  In all my years of reading, in all the hundreds or more books and many "Life of..." -- nothing is as despicable as this.  I consider it blasphemous.  It is an insult to God's sanctity and Our Lady's immaculate soul.  Please don't let such thoughts and imaginings as she writes even enter your mind.