Plugins provide additional features that aid in helping you make your map, from insanely quick sector tagging to displaying statistics or building stairs.
First, pick a plugin from this page here: http://doombuilder.com/index.php?p=plugins
(There are alternate pages hosted by third parties, but this page contains most of the ones that you will be using)
For demonstration purposes, I downloaded the "Tag Range" plugin, created by Pascal vd Heiden.
The installation proccess is actually very simple. First exit all open instances of Doom Builder. Then, navigate to your main directory for Doom Builder.
Then, using your favourite archive explorer (pictured here is WinRAR), unzip the .DLL file into the directory labeled "Plugins."
And that's it! Easy, wasn't it? To make sure the installation went without a hitch, open up Doom Builder, and you should see a new icon at the top of your toolbar. Note that the "Tag Range" plugin only applies to sectors/linedefs mode, so don't panic if it's not there in things mode.
