I received Castle from my parents as a birthday present. The other three I picked up on Amazon, very cheaply. I plan on buying one every few months to complete the collection. I prefer the black and white editions, on paper, but he has updated the series in color and also has many titles available for Kindle.
Fast forward to something I didn't know. Some of them were adapted to documentaries by Unicorn Productions. Even better, they are on Youtube.
I have yet to find a better streaming source, but if I find these elsewhere, I will let you know.
I was going to watch a little Netflix, but this is much better. That and order the few books I am missing from the series. The links below are paid ads and will take you to Amazon.com.
Kindle or Print
Ads provided by Amazon help fund this website by remuneration.