Random Thing, Sherry's special gift is Herb Salad, and Joan sells that most of the summer, so it's an easy way to befriend Sherry.
Ushi No Tane x9 is a great site that has practically everything, check it out.
Felix and Dirk both like beetles, (+500 FP) get them on trees at nighttime during the summer.
To get into Emiko's cave you need to be in Year 2, go up to the area after 8 PM on a non rainy day, it will open up.
If you ever see a sparkle on the ground, go up to it, and hit 'B'. You may often get cool things, such as coins. On rainy days you sometimes get Silver (480G during Bazaar) or Gold (840G during Bazaar) coins.
If you're married, and you had a child, if it was born a male and say you wanted a female, just switch the game off and start the day again. The gender is set at birth!
Hope that helped.