Spell making is really that simple. Once you have a basic idea of how spells and magic work, going about creating one really only takes a few basic steps. How simple or complicated you want it to be after that is completely up to you and your preffered style of spell work.
A book of shadows is a collection of things that pertain to your magical practice. You can make it however you would like. The things you put in it will be very personal, although some common ones are correspondances, moon phases, spells, rituals, etc. I personally have mine in a three ring binder so I can move pages around. Some people prefer a journal or notebook, and even others have it online. Be creative and do something that works for you.