Lurk on the CQRS/DDD list [1], lots of good info there. I'm not aware of any textbooks on ES per se but there are a few good books on areas that overlap. [2] [3] [4]

[1] https://groups.google.com/forum/#!forum/dddcqrs

[2] https://www.amazon.com/Enterprise-Integration-Patterns-Desig...

[3] https://www.amazon.com/Implementing-Domain-Driven-Design-Vau...

[4] https://www.amazon.com/Domain-Driven-Design-Tackling-Complex...