Memrise all the way. Definitely.

Go to memrise.com. I know that many have found success there.!

http://www.memrise.com/blog/why-forgetting-is-the-secret-to-learning-vocabular/ I propose three key ingredients for learning vocabulary: 1. Context You need to hear, see, and use the word in a variety of contexts. Instead of studying vocabulary words in isolation, study them in the bigger picture - sentences. How do they relate to the real-world and everyday life? How would you use the word in a sentence? Are there certain grammar constructions that are either frequently used with it or must be used with it? 2. Emotion Having a strong emotion tied to vocabulary exposure helps us retain the information, although, for whatever reason, some random words may stick just because and others won't stick at all. For example, an experience that is funny, enraging, shocking, or sad will be more memorable than one that is boring. Thus, encounters with vocabulary in speech will likely be more memorable than just staring at words on a paper. A class full of laughs with a tutor may provide an extra boost in your learning process. 3. Need The vocabulary you study should be relevant to you. Of course, as you grow more and more advanced, you may branch out and extend your range. However, to start, try learning basic and common words and phrases. Then, choose words that you frequently come across along with words that you would need to know in order to talk about yourself, your life, your interests, etc. A spaced-repetition system or online flashcard and quiz tool (memrise.com, ankisrs.net, quizlet.com) may assist you in retain vocabulary, grammar, etc. However, many people have learned to speak a language fluently without using these additional tools. For something you have less exposure to or time to practice with, try squeezing in any time you can get during transit, your morning routine, exercise, housework, etc. Read, listen to audio, watch movies, practice speaking and writing, and use online study tools such as ankisrs.net.

I've found a few resources that I really like to use as far as a list goes. http://www.topikguide.com/2010/05/most-common-korean-verbs.html - 500 most common verbs https://sydneytoseoul.wordpress.com/2012/08/04/top-100-most-useful-korean-adjectives-full-list/ - 100 most common adjectives (side note: this website also has a 100 most common verb list and PDF's of those available for download). https://sydneytoseoul.wordpress.com/resource-list/ - This is a resource list that I use to aide in my online learning endeavor. Hope this helps! ^-^

I think you should select books based off of your interests, current language proficiency, and goals (both overall and on that specific "mission". Ex. Improving reading speed, increasing vocabulary, reading along with audiobooks, etc). Overall, reading material at or a notch above your current level will be best. Without challenge, there can be no growth. You won't acquire new knowledge of idioms, slang, vocabulary, grammar, colloquialisms, culture, etc if you're only working with what you already know. Choosing reading material far above your level, unless perhaps you're skimming for some new information and not for understanding, is not a good idea. It can be frustrating, overwhelming, and a waste of time trying to muddle through advanced (relative to your current level) grammar and language.