A highly recognized and respected source on Revelation, The Theology of the Book of Revelationby Richard Bauckham is not an easy read. It’s a book written by a scholar for scholars. But it’s also the Revelation commentary cited over and over again by other authors and speakers. Bauckham has done his homework, and he knows what he’s talking about. 
If you’re really looking to dig deeper into this Revelation stuff, and you’re up for a little challenge, it will be well worth your time to grab a copy of Bauckham’s commentary and dive in. He makes a strong case for the value of studying Revelation in modern context, saying, “Revelation has an unexpected theological relevance today: it can help to inspire the renewal of the doctrine of God which is perhaps the most urgent contemporary theological need.” 
Purchase a copy here.