Learning Japanese on your own is not necessarily, hard. As others have pointed out, it depends on your motivation and passion for the language. Most people get a teacher because it gives them the extra push to study more. I'm self-taught. I learned Japanese from reading language books and watching Japanese shows. If you want to learn Japanese, be sure to also watch something. Don't just read. Watching and listening to Japanese, helps sharpen your hearing senses to words and also gives you a better understanding on how it's spoken.
I love Goodreads. I always use it to check out new releases for both fiction and non-fiction. It only has book reviews, which is a must for me before purchasing any book. I also love the many "genres" you can search from. I used to use Amazon to check for reviews and look for new books, but not anymore.