If you do not know what an OC Book is, it's not too hard to understand really. Essentially it is a book for you to develop characters you wish to use in roleplays. You can chose to use different OCs in roleplays, but I do warn you, it gets very confusing. Having a few structured characters goes a long way.

If you want an example of an OC, you can check out my old OC Book compared to the new. The new one is much more developed and detailed, especially as I use the character and learn more about them as a person. You will grow to love your OCs and feel almost a bond with them, hats how you know you are doing it right.