Wall switches/simple dimmers deal with one function only, the starting/stopping of nominal 120v ac electricity going to the fixture which contains the load. Only the load should have a neutral (white) line leaving it plus the switchable line from the switch entering it. So your old switch should have two wires connecting to it, one bringing in 120v power (black?) to the switch and the other (hopefully not white) when switch is "ON" sending power to the fixture. The dimmer you purchase will contain installation instructions to thoroughly cover all this without doubt.

Here is a link that might be useful: Install dimmer

Yes, from what you have described, the black went to the lighting circuit of the ceiling fan and the red went to the fan motor. Cap off the red in the switch box, for added safety, and then connect any standard dimmer to the black wire going to the newly installed ceiling light.

The connection to the dimmer needs to be black on both ends, incoming from the power and outgoing to the light. The white does not go on the dimmer unless the dimmer itself needs it to operate.

Open up the box and post before disconnecting everything.

Removing ceiling fans!... what is Al Gore going to say? Well at least you should have extra-strong ceiling boxes left behind for hanging your new light fixtures.

Seriously, the other variable besides total wattage of the chandelier, is whether it uses incandescent bulbs ("standard" dimmer), or one of the newer technologies (compact fluor., etc.) which requires a more "advanced" dimmer.