The Ore sites are in the Continental Map they are little blobs on some of the areas you conquered on the Mars portion of the Continental Map. (One oddity is you cannot click "near" the ore image. that will take you to the area you conquered! you have to click directly on the image of the ore. )
But.. before you an make ore.. you have to have Credits. !!! (Credits .. lots of them) are required to make any Mars Ore.
To get the Credits you have to start your Mars Colony. The small spaceship to the far middle right on the screen is entrance to your Colony.
You have to get some housing by doing the Research to gain some of the Houses you can place in eh Colony. The more Houses the more Cedits you get.
Starting out I suggest fill all you can of the four hour 2x2 houses. They can be good to use for a long time..