I put in double gang box, second switch, ran second cable from light switch to ceiling. So there are two identical cables from switch to fixture. The existing switch had power in to it. So i need to connect the two switches and at the ceiling use one black for light and presumably black from second cable for fan. How do i connect the two switches?
If the line power enters in the switch box, you will have a single (probab black) line hot that you want to connect to one side of both switches. The most straightforward way is to make two pigtails (short ~6 inch pieces of wire) (black) and connect them in a wire nut with the line hot (so three black wires in the one nut). One pigtail is connected to one switch and one to the other.
You could also use a single pigtail and pass it from one switch to the other. This means that this single pigtail would be stripped for an inch in its middle and a loop made which goes around the connection screw for one switch and the same piece of wire carried on to the other switch. This saves on space in the box, if that is a problem. (You could even do this to the line hot and have no pigtail at all, but I don't like to do that because I like to preserve insulated length on the incoming line hot.)