How do you mine in Harvest Moon DS?

It's simple really. Go to the excavation site (where you find Flora and Carter spending most of their time) carrying your hammer after they all leave. (Usually around (9:00pm-9:30pm) You should start an event where Carter enters looking for you and asks if you could use your hammer to help him open a tunnel he thinks he's found. You will agree and Tadaaa! There's your mine. Note that this sometimes takes a few tries. Just exit the mine and reenter a couple times. Also, there are three more mines you can explore beyond this one. To open the rest, reach the bottom level of the current mine you have open and defeat all of the dark creatures there. When you return to the surface simply wait until 9:00pm - 9:30pm again and enter with your hammer as you did before. The same thing should happen and you'll blast a secoond (or third or fourth) hole in the wall. To open the Fourth you will have needed to make it to the bottom of the third (it contains 999 floors) AND the 255th level. I hope this information was helpful! I can not find any valuble items in my game though (different person)