This book a PDF (206 pages) - organized in a way that will easily allow you to learn 100 of the most common Korean words within a month (or less time depending on you). Since it is a “picture book” with lots of pictures, the download file will be large so be aware. There are 4 different sections categorized by week (week one, week two..). You can access links to Quizlet to study the words and test yourself. The words are organized by verb, noun, adjective, and adverb and are presented in that same order throughout the book so you’ll learn about 25 of each.
 
In total there are 100 words. Each word has at least 1-2 examples (185+ examples total) showing how it is used in a sentence. I recommend beginners use this book alongside your regular grammar studies for the best results. Also to learn even more, I suggest looking up words you don’t know - using Naver Dictionary - from the examples as well. Upon purchasing, you’ll be able to access it almost immediately.