I color a lot after I'm done my homework in the evenings or when I'm watching a movie. The illustrator of my book is Johanna Basford and its called Lost Ocean.
I've done ten pictures since November. I've done three fishbowls, two sharks, one fish, one heart, one whale, one eel at the moment I'm coloring an octopus.
I use staedtler triplus roller pens. At first they are hard to use but you have to get use to them. They have a fair amount of ink in them for the price. I've done nine pictures with the same packet and they're just running out now.
I would definitely recommend getting a coloring book. Every one is different. I have lots of fun coloring! You can get them at any book store like Easons.