Guide to being a dungeon master

1. Familiarize yourself with the game rules: Before you start running your first game, it is important to familiarize yourself with the rules of D&D. Read the Player's handbook, possibly the monster manual and dungeon master guide to get a good understanding of how the game works. However, it is not necessary, but can help you along the way and give you inspiration for how you can manage your game and story. 

2. Plan Your Campaign: A D&D campaign is a series of adventures that take place over a long period of time. Before you start playing, you need to have a general idea of what your campaign is about and what kind of adventure your players will be going on.

3. Create a World: As the DM, you are responsible for creating the world that your players will explore. This includes creating maps, thinking about the history and culture of the world, and deciding on the races, classes, and backgrounds of the non-player characters that your players will interact with.

4. Write and run adventures: Adventures are the individual stories that make up your campaign. As the DM, you are responsible for writing and running these adventures, which will include combat counters, skill challenges, and role-playing opportunities. Instead of starting from scratch, you can choose to use pre-written adventures such as this. 

5. Communicate with your players: Communication is key when it comes to DM. You must be able to listen to your players, answer their questions and help them understand the rules of the game. You should also be able to give feedback and help your players grow as roleplayers.

6. Be flexible: D&D is a cooperative game, and your players will often take your adventures in unexpected directions. As a DM, you must be flexible and able to adapt to your players' actions.

7. Have fun: Being a DM everywhere should be a fun and rewarding experience.

Most of the rules and guidelines for being a Dungeon Master are found in Dungeon Master's Handbook