[JoelPM]

As a long time Java programmer I recommend these two:

http://www.amazon.com/ERLANG-Programming-Francesco-Cesarini/...

http://www.amazon.com/Programming-Erlang-Software-Concurrent...

Okay, just kidding. =)

On a serious note, Effective Java is one of the best out there.

[markmywords]

Both of these are great :)