Wanted to get my thoughts out for others who are trying to learn and use Erlang having a similar career background as mine. All along in my career, i've learnt and applied several "procedural" languages (PP) starting with C,C++,Python,Lua,C# and some java. Once you've understood the basics through one of these languages it is easy to learn the other since they are all based on same fundamental principles of programming language design.
Now Erlang basically a Functional Programming (FP) language was some thing I was not exposed or used to before in my career. FP radically requires a different style of thinking from PP. So if this is your first FP like myself, don't buy a book that teaches you the Erlang (or say other FP) language as it will not get you far. As you to start to do serious programs with FP after learning some language basics ,your brain will naturally resist this different style of thinking and you'll either feel hard to continue and/or quit. You'll feel very warm and happy along with others to bash FP/Erlang.
To be comfortable and learn FP naturally it is better to understand the foundation of this FP which is lambda calculus. Lambda may look even weird on first sight, feel dizzy for quite a while but once you get a hang of this and solve couple of lambda calculus problems you'll now find your style of FP thinking. So my suggestion in one line is
Start with Lambda Calculus if this is your first functional programming.