Basic guitar chords? Are these correct?

I'd say that your "D" chord is correct and your "G" chord is correct but your "C" chord is wrong. It should be First finger first fret on the "B" string second finger second fret on the "D" string and third finger third fret on the "A" string. Also you don't have to fret the "B" string on your "G" chord if you don't want to. Another way of playing the "D" chord is to bar the 3 strings at the second fret with your first finger and use your second finger on the "B" string on the third fret. I find it much easier.