Is it praiseworthy to extensively research the details of the delights of Paradise in scholars' books, or is it better to devote oneself to worship to increase good deeds? And what books do you recommend?

There is no harm in listening to lectures about the nature of the bliss of Paradise and researching it, for that raises one's aspirations and encourages good deeds, and it is a righteous act. However, if the matter transforms into mere culture and knowledge of details without striving to act, then this is an engagement with the lesser over the greater. Imam Ahmad ibn Hanbal was asked about the distance between us and the Throne of our Lord, and he replied, "The supplication of a Muslim whose prayer Allah answers," thereby guiding towards action and abandoning what may not concern the servant.