Hellow D-Ponymon. Groups you should look into for your planned stories that I know about so far would be the ,
Human in Equestria group.
The Human Harems group.
The Anthropomorphics group.
The Humans Falling in Love with Ponies group.
The Crossovers group.
The Clopfics group.
The Equestria Girls fics group.
And the Humanized Ponies group.
And groups dedicated to specific characters if you want. Hope this helps you out. Also if you click on the Groups button next to your username under the site's banner you will be able to search for other groups.

Good luck with all of your endeavors.