Is this book good to start with if you don't know any Ruby already? Or should you already be familiar with Ruby? (Same with the Rails technique chapter. Do you need to know some Rails before attempting to read that chapter?)
Yes, we advise that you at least have a basic grasp of Ruby before you dig in. You don't *have* to, but I think you'll be able to understand it a lot more, especially since we've geared the book towards answering "I know Ruby...now what?"