3. Setting Up SKSE and SkyUI - Zerofuse/Skyrim-Modding-Guide GitHub Wiki
SKSE is a Skyrim script editor. Nothing more nothing less. However it is vital for almost every single mod to function properly.
To install it, simply point it to your Skyrim install directory. This is normally under C://Program Files(x86)/Steam/SteamApps/common/Skyrim.
And that's it. Make sure the SKSE components are inside your Skyrim directory (like the skse_loader.exe).
Now for SkyUI, a Skyrim UI mod that is very PC friendly and most mods now utilize it for it's Mod Configuration tab.
Since you downloaded it manually, we must install it manually with MO. Go ahead and click the button in the top left corner (Install a new mod from an archive). Locate the SkyUI .rar and install it. Go ahead and click the box to activate it, if it isn't already.
Once installed, go ahead and click the "Pick a program to run" button. Go ahead and in the title area put SKSE. In the Binary section, click the three dots, from there select the skse_loader.exe located in your Skyrim install directory. Once finished, click the run button and see if it launches. If it does, then congrats! You're ready to get into Skyrim modding, if it doesn't then your probably did something wrong.
From here, click the Essential Mods page.