The ''best way'' to improve depends on each individual, you have to try different methods. Novels aren't exactly the best way to improve if you're a beginner as they tend to be kinda complicated, if you like reading starting with manga is pretty good as it has less text and the images help you understand better the situation. Plus, plenty of mangas out there come with furigana. Video games are pretty good, too. Now, if you want audio I suggest doramas before anime as doramas tend to use a more realistic language. Light novels and novels are better when you're above intermediate level, but light novels vary a lot, some are easier to read and some are hard.
In my opinion the best way is to study the Japanese language in Japan, in a language school. I can recommend you the school where I`m studying currently, I`m very happy with it, after studying 3 months with them (starting from zero) I passed the JLPT exam N5: http://jclischool.com/