Hi. I'm pretty new to Shadowrun. I dug Returns pretty good. So I downloaded some mods from Nexus and...I don't know what to do now. There aren't any readme files in the zips and no instructions on the website. I'm confused.

Hello. So, first of all, you need to find out if your files are appropriate for your game (I assume that you have latest patch). There are three games: SH: Returns (the one with Dead Man's Switch campaign), Dragonfall and Hong Kong. Any good plugin should have it written somewhere in the description.
Secondly, move your archive files with plugins into your documents folder/Shadowrun *name*/ContentPacks , where the *name* is Returns, Dragonfall Director's Cut or Hong Kong depending on the game in question.
Here are the paths as outlined on the editor wikia:
Windows:
C:\Users\*current user*\AppData\Local\Harebrained Schemes\*game client*\ContentPacks
OSX:
Users/*current user*/Library/Application Support/Harebrained Schemes/Shadowrun Returns/Content Packs
Linux:
/home/*current user*/Shadowrun Returns/Shadowrun_Data/StreamingAssets/ContentPacks
Your exact path may vary.
Thirdly, just open the game and check your "New Game" option. Your brand-new plugin should be sitting there, waiting for you to play it.
Sidenote: Each plugin should have inside its .zip file folders like data and art, and, most importantly, project.cpack.bytes. All of these should be included already and I write this just so that you could verify it.

That worked! Thanks for the tutorial.