Divine Mercy Consecration

If I miss a day or more than one day of the reading, is that OK?
Yes. Fr. Michael Gaitley says, “Of course, 33 days is a long time to be on retreat, and it just might happen that, despite our intentions and best efforts, we’ll miss a day (or days) of the readings and prayers.  If this happens, we need not get discouraged, and we surely shouldn’t quit! Instead, I suggest that we simply read the text for the days we missed as soon as we can and keep going with the retreat. The Lord knows what’s in our hearts, and if our desire truly is to make the consecration, we shouldn’t let any temptations stop us.”
Do I have to have read other books first such as 33 Days to Morning Glory, before reading 33 Days to Merciful Love?
No. While many people may find it beneficial to read other books such as works on mercy and 33 Day to Morning Glory, it is not necessary to read another book before reading 33 Days to Merciful Love.