First, go to your main Documents folder or whatever. Create a new folder called "Add-Ons".
Copy the script files out of your real Add-Ons folder into the one you just created. If you are making a weapon, make Sound and Shapes folders inside the Add-Ons folder and put the relevant files in them.
Right click on that Add-Ons folder, use an option like "Send To > Compressed/Zipped Folder". Alternately, if you have programs such as 7-zip or WinRAR installed, you will find a list of options on how to put it into other types of archive like RAR and 7z.
A new file will be created called Add-Ons.zip. Rename this to whatever your mod's name is.
Upload this file to a hosting website. Google Pages, host-a.net and mediafire.com are all free to use. (The first two require you to register, though, but are usually more reliable and don't delete files after 30 days)