Is it permitted to learn Torah with one's wife?
And if so, are there any special recommendations for what to study with her?
Generally speaking I understand that men don't take women as Chavrutas, related or otherwise.
There is no reason to prohibit learning Torah with one's wife, and indeed many husbands and fathers learn with their wives or daughters.
Recommendations for what to study is a personal preference, as the gemara in Avoda Zara 19a writes
Rabbi Yehuda HaNasi says: A person can learn Torah only from a place in the Torah that his heart desires, as it is stated: But his delight is in the Torah of the Lord, i.e., his delight is in the part of the Torah that he wishes to study.
Depending on the person, learning the parasha of the week, the meaning of the holidays, emuna might all be relevant. There are also certain areas of halacha which are critical to a woman, e.g., Shabbat, kashrut, nidda. Examples of books I have found helpful here are
You can ask more specific questions if looking for recommendations in specific areas (e.g., emuna).