Srila Prabhupada said that his books are like a sweet ball. No matter which side you start eating from it is always tasty. Still, the best way is to go systematically through the books one after the other – the Bhagavad-gita, The Nectar of devotion, Srimad-Bhagavatam, Caitanya-caritamrita. In those books we have a word for word translation of each verse, then a translation of the verse, and the purport by His Divine Grace A.C. Bhaktivedanta Swami Srila Prabhupada. The purport helps us to understand the verse in a proper perspective.
In the beginning it is OK to read only the translations of the verses in order to get the whole picture of the chapter or of the book. But then we should go back and read the verses together with the purports because in this way we will understand the actual meaning of the verses.
Srila Prabhupada said, “My purports are my devotional ecstasies.”