Can someone for the fucking love of god explain how to add the mod files in step by step detail to the point!
OK, as a former noob on this very subject I will do my damnedest to help you out.
1) Download your preferred mod and extract it to some temporary folder somewhere of your choosing.
2) Open up your Monster Girl Dreams game folder. Then open the "game" folder. There's a folder in there called "Mods." Open that and keep it open for now.
3) Go to the mod you saved and open it until you get to the last folder layer that is just the mod's name. It's usually two layers deep. So, for a fictitious example, the "Princess Peach v.4" folder you extracted will open to a "Princess Peach v.4" folder, then open that to see a "PrincessPeach" folder. If you open that and get folders named "Adventures," "Images, "Events," and so forth, just go back one step.
4) Copy that last layer of mod folder (in our example, "PrincessPeach") to the "Mods" folder in MGD.
5) Make sure your MGD game is saved at the town square to ensure that your mod will work properly.
6) Start the game! Be advised, when you click an option on the town menu, especially "Go Adventuring," there may be a few seconds delay as the game absorbs and implements the new mod(s). Be patient.
7) Enjoy!
8) Any questions, please ask. Every one of us was once new at this once after all.