I've been interested in playing mods for Civilization 5 lately. How do I go about finding them?
Two good options I use:
Go to the Steam Workshop site for Civilization V
As of version 18.104.22.1684, Civilization V's Steam Workshop contains a list of mods with popularity and rating details, indexed by category and searchable with free-text. Mod developers don't have to publish their mods there, a mod is just a file you can download, but it seems most developers do indeed publish on that mod hub.
Go to the Civilization Fanatics Center
The popular civfanatics website has a download section with many mods, maps and more; you can also browse its forums directly. Mod developers typically publish a lot of details in these forum threads and you can also read what other people think about the mods, so I recommend browsing that forum if you're looking for something new and interesting.