Most magazines, though, run “contests,” of a sort. There are some specialized contests with big prizes, like Shueisha’s Silver Tiara competition, but most of them are ongoing. Basically, all of the submissions for that magazines are collected monthly or quarterly, and the best submissions are given monetary prizes and advice, and their name printed in the magazine. When you are deemed good enough, then your story will get a contract for printing, and voila! You’ve made your debut! From there, you are assigned a continuous editor, and they will work with you to make a story suitable for serialization or more stand-alone stories.