First of all you need the SteamCMD. You can download it here:
https://steamcdn-a.akamaihd.net/client/installer/steamcmd.zip

Now you need to execute this file. After that we type the following into the console:
This will create a folder with the name "dayzserver" and it will put in the files in this folder.

After that you need to login into your steam account:

Now you will be asked for your Steam Account password and your Steam Guard Code.
You will be logged off of your Steam Client!
An anonymous login isn´t possible for creating an DayZ Server.

IMPORTANT: The password won´t be shown in any way, so you basically have to type blind!
After you´re done, u´ve to press, as always enter!

Now you can start the download with:

If the download was sucessful, you have to type
in the console to close the SteamCMD.

Now you can restart your Steam Client, you should be logged in just normaly.

You can find your "serverDZ.cfg" in your Root DayZ Server folder.

If you want to know, what does which command and what can be added, take a look here:
https://community.bistudio.com/wiki/DayZ:Server_Configuration

If you´re using a whitelist, you should also edit the file "whitelist.txt" of course.

The best option is to create a .bat file in your "DayZserver" server folder (e.g. RUN.bat)
Edit the .bat file with following code:

I would also recommand to add this in:
This command will make sure, that the player profiles will also be saved in the server folder.

I can not see my server / No one can connect to my server
Please make sure, that you have opened all the required ports in your router. If the everything is set correctly, but the problem still occurs, please contact your internet provider.
Or look for your router model here:
https://portforward.com/router.htm

Is there another way instead of opening the ports?
Yes, you can also host your server through a VPN network like "Hamachi". Of course only the people in the VPN network will be able to join the server then.
If forwarding your ports doesn´t work, please contact your ISP, i won´t be able to help you.

How can i change my server port?
Just edit the bat file with "-port=27015"

The SteamCMD download failed! What should I do now?
Mostly you just need to retry the download, then the problem should be fixed.

How do I update my server?
Just open the SteamCMD and login again, then retry the Step "Downloading the files" it will be checked which files need to be updated.

To automate these steps to setup/upgrade a server, i created a tool, the group can be founde here:
http://gtm.steamproxy.vip/groups/ServerTool

The tool itself is hosted on Github, which can be found here:
https://github.com/Zeromix9/ServerTool

I hope, that will help you in the future!

If you like, you are also welcome to leave a small donation.
https://paypal.me/Zeromix