I'm am an experienced developer in other languages like C#, VB.net and C++, but a real newbie in Ruby. What Ruby book do you think should I read first?
Why's Poignant Guide to Ruby is almost certainly unlike any programming book you've ever encountered and well worth reading (think, cartoon foxes). This is actually a serious book on Ruby - just with a delicious facade of lunacy.
Given that you've tagged your post with RoR, you'll also want to read Agile Web Development with Rails, which will not only teach you to develop rails apps, but more importantly, develop them the right™ way.
The Ruby Way, 2nd ed. Heres is the slashdot review.
This is the second book about ruby I had purchased (the 1st: Programming Ruby), and I prefer this.
Check out "The Ruby Programming Language" by David Flanagan and Matz for a no nonsense, classic style book on Ruby programming.
I read Programming Ruby (pickaxe) first, then The Ruby Programming Language. I'm happy I read them in that order.
The pickaxe book gives you a good overview of Ruby and it has a good reference section too. After familiarising myself with Ruby through the Pickaxe, I went to the much more in depth The Ruby Programming Language. Partially written by Matz, Ruby's creator, it goes quite deep into Ruby and provides lots of great insight into making use of Ruby's many features. I has a great metaprogramming section too.
Since you tagged the question rubyonrails
, I'll add Agile Web Development with Rails.