HI, I was doing allot of research recently on Japan's annexation but i found there was a major lack of information. One of the areas I want to know more about is how Japan took over Korea and how they maintained control. I coudltn find any information of wether they used direct or indirect control. What rules were inforced. Also I found articles claming that the Japanese used forced labor yet there wasnt any more information.
I see you've posted this question in /r/homeworkhelp. I'll give you a couple of books to check out for more information and a brief rundown.
Korea was under the influence of China until the mid 1870s, at which time the Japanese forced themselves between China and Korea with the Treaty of Ganghwa-do (there's more than 1 treaty by that name, FYI). The Chinese and Japanese agreed to a deal whereby anytime they were planning to send soldiers to Korea, they'd notify the other party. In 1894, the Korean countryside erupted in rebellion and the Chosun court (Korea) asked China for help in putting down the rebellion. The Chinese obliged but didn't inform Japan who took offense and started the First Sino-Japanese War. The Japanese thoroughly beat the Chinese and Korea was quickly falling under Japan's influence.
During the 1890's, Japanese business interests expanded in Korea, the Japanese military was occupying various parts of Korea, and the Korean government was weak. The Japanese assassinated the Korean queen and the king and prince hid out in the Russian embassy for around a year, for safety. The Japanese and the Russians went to war in the early 1900's and more Japanese troops came to Korea. The Japanese then forced an unequal treaty on the Koreans, making them a protectorate and then outright annexing them by 1910.
For more basic, yet in-depth, information, check out A History of Korea by Michael J. Seth. It's a basic college textbook on Korean history, but it's straightforward and will cover the basics. Another book I enjoyed was also titled A History of Korea by Kyung Moon Hwang. It's a lot shorter, but it's written in a much more entertaining, storytelling style. There are lots of anecdotal stories in it, and plenty of links to primary sources, should you choose to read more. Beware information you read on this topic - modern Japan and Korea are still sore about the topic and various right-wingers on both sides push their agendas. Lots of Korean sources will make it sound like hell on earth while Japanese sources will take a benevolent and paternalistic view of helping those silly, backwards Koreans.