There was a recent thread where we debated the appropriateness of Catholic “sex manual” type books. There were some differing opinions, but IMO, I would stay away from them (Holy Sex!, Theology of the Body, etc) because it seems intrusive.
I am a little up in the air about marriage guides, a gift like that could be interpreted as a sort of insult – like, you just walked down the aisle, but I’m worried about you already!
For those reasons, I agree – a Bible is a nice way to go.
I also thought a nice framed Wedding Blessing might be nice – like this:
May God be with you and bless you.
May you see your children’s children.
May you be poor in misfortune
and rich in blessings.
May you know nothing but happiness
from this day forward.
–Irish Wedding Blessing
Just a thought.