Since I don't have a ball winder, I used an old paper towel roll to wrap all my yarns into a magic ball. There are a couple ways to join the ends of your yarns together, you could just knot the yarns together but I used the Russian join method for mine. This youtube video demonstrates how to do this well. It's not a hard technique to get at all.
And this is my magic ball! It's a really good size, I don't think I'll run out while making my toy. Speaking of, I still need to figure out what toy I'll be making. I have it narrowed down to two now, it will be either Otto the Monster or Gordon the Jellyfish. I can't wait to get crocheting with this ball!