Chatting with you for one night  is more profitable than studying for ten years.

解释 ( paraphrase )
和对方一晚上的谈话，胜过自己读了十年的书。
这条谚语夸张地说明对方一番谈话给自己的印象深，教育大，收获超过了多年所读的书本知识。

This proverb contains a high form of praise, the effect that one is deeply impressed and greatly enlightened by someone else's conversation.

君：对人的尊称。
      A respectful way to address a man.

夕：晚上。
      Evening, night.

十年：多年的意思，不是实数。
         Many years (not a definite number).

同义词 ( synonym )
听君一席话，胜读十年书。
一席话：席，意为席子。一席话在原来的故事里是指同坐在席子上说的一番话。
In original story, the phrase means having a conversation during sitting on a mat together.

造句 ( example )
她在这方面做了很多研究，和她聊这个课题，我明白了许多。真是“与君一夕话，胜读十年书”啊！