Raspberry Pi to Arduino Shields Connection Bridge

I have Linux experience but I haven't played with any electronics in quite a few years. I am using this in conjunction with the book Raspberry Pi Home Automation with Arduino. I am easily entertained as I was pleased to complete the first task which is to get a LED blinking. Keep in mind there are other connection bridges available which I'll probably take a look at. This came from Spain but it beat it's projected arrival date by about a week.