To date I've authored three highly acclaimed tutorials for the BYOND beginner. They are mirrors of each other; each coveres the basic concepts of the DM language while teaching the user to program a different type of game. They were written with a strong care for the perspective of the newcomer, and assume nothing in the reader, least of all a knowledge of programming. Zilal's Beginner Tutorials have become a standard, the starting block for anyone who wants to learn how to code in DM.
ZBT - Action/RPG edition. Apply coding fundamentals to the creation of a world of monsters and combat.
ZBT2 - Strategy/board game edition. Apply the same fundamentals to the creation of a simple board game.
ZBT3 - Text MUD edition. Learn the BYOND basics in the context of starting up a text-based RPG.