help me choose a ruby book

could any1 recomend a book i could buy for my girlfriend shes a computer
programmer and deals in ruby rails i dont have a clue , there are a few
on amazon could sum1 help me pick a decent 1?

I have to throw in a vote for David Black's Ruby for Rails:
http://www.manning.com/black -- It gets to the core of the language -
so it's the gift that keeps on giving!

Best,

-r