depends on where you intend to upload it.
If you intend to upload to Steam, there is a specific procedure and file that Steam wants (it is really just a zip of the entire contents of the mod as it appears in the game's MODS folder). See
Modding Basics (by ceej12) This is a guide on Steam, where ceej12 outlines the steps needed to create a new mod and then upload it to Steam.
If you intend to upload elsewhere you can
still just upload that same xxx.civ5mod file that is needed by Steam, and users can unzip that file manually once they have downloaded it from Dropbox or wherever.
Alternately you can zip (and then upload) the entire contents of the mod's main sub-folder taken directly from the game's MODS folder. See
zip your mods and attach tutorial (by whoward69) for an example of how you could zip the needed version of the mod and use that zip as an attachment here on the forum. Whether you wish to upload your zip to Dropbox or attach to a forum post, or upload to some other non-Steam file-sharing site, it is the version of the mod specified in the tutorial by whoward69 that is needed when creating a zip of the mod. Everything in that mod-folder is required, including the modinfo file, which is why William Howard specifies you should just zip the entire folder of your mod.