Hi barbiknowsall, and welcome!
Noticing you are in Minnesota, by any chance are you writing for
Anandatandava (Roy), who has been posting here from prison for several years with the help of others?
It this is for someone else, it will be good to know more about the circumstances, potential interest in spiritual practices, experiences, etc., so we can offer whatever assistance we can.
It should be mentioned that AYP is not only an online resource. All but one of the 13 books are available in paperback from Amazon and other sources. They are shown in the right side border here, and are
listed with descriptions and links here.
If there is interest in other writings, there is an
extended book list on the AYP website covering about 500 books. Links are provided from there to Amazon and other sources where additional books can be found by referrals or searches.
As for opinions on the books, others may wish to chime in here with recommendations.
The books are offered for the reader to decide. With bhakti (spiritual desire), we will be inclined to read. Hopefully we will be inclined to practice daily also, as this will lead us to greater openings.
Wishing you and your friend all the best!
The guru is in you.