Installing DynMap is relatively easy. Here's how:
1. Download the relevant version of the plugin for your server version from: http://dev.bukkit.org/server-mods/dynmap/
2. Then upload the plugins .jar into the "plugins" folder in your service directory. We recommend using FTP to do this. If you are not familiar with how to use FTP, please follow our "Using FTP to Access Server Files" FAQ.
2b. Restart the server for the config files to generate.
3. Open up the configurations.txt file
4. Change the "webserver-bindaddress" from 0.0.0.0 to your server IP (DO NOT include your server port!).
5. Change the "webserver-port" to a port between 8000 and 9000. We recommend to NOT use the default 8123 port and to use another number!
6. Link the plugin to an SQL Database so that it does not overload your disk space with unneccesary image files (DynMap can use an extreme amount of space otherwise). To do so:
- On one tab open the Files > Config Files > DynMap configuration.txt page of your control panel (it should be near the end of the list of configs, it's alphabetical but case-important too so d comes after X,Y,Z,a etc...).
- On another tab open the Advanced > MySQL Database page of your control panel, and click Create on the left hand side to make your database if you have not already, after which it will show the details needed to connect to it on this page.
- In the configuration.txt file find this section:
- Edit it to look like this using the details listed on your MySQL Database page of the control panel to replace the  parts, and note the added and removed #'s at the start of the lines which are important:
Then save changes and load the server back up - Make sure to check the console for any errors from DynMap during setup, if it gives any the details entered in the config may be incorrect and will need to be corrected and the server restarted to link it to the SQL correctly - then re-render your map as normal (Such as with '/dymnap fullrender') and it will save it's images to the SQL and not to the hard drive, so your space won't be filled by it!
Once it is set up with the SQL correctly you can then delete any flatfile images that were already generated to free up the space they were using - to do so delete the /plugins/dynmap/web/tiles/ directory of the server files (the tiles folder only contains the flatfile images so deleting just this folder will not effect the plugin setup at all).
7. Run /dynmap fullrender world ("world" is whatever your level-name is set to)
8. Access your server via http://serverIP:bindport (This will update as the render runs to show the explored chunks).
9. Pat yourself on the back if it works :D.
DynMap on Forge
If you are using Forge on your server you can also use the mod version of DynMap which you can get here: https://minecraft.curseforge.com/projects/dynmapforge
Simply downloaded the mod file for your specific Forge version from their files and then upload it to your servers /mods directory and restart the server. The configuration files will then be in the /dynmap directory of your files, but otherwise setting the mod up is the same as the above steps (with any image files, if they need to be removed, being in the /dynmap/web/tiles/ directory)!