The orbital illustrations for the d subshell are complicated and not really necessary to understanding how to fill in the orbitals with electrons. You can represent the 5 orbitals of the d subshell with 5 small horizontal lines on paper. You fill up the orbitals with electrons evenly. The electrons are usually represented with small vertical lines drawn on the horizontal lines. So put one line on each of the 5 orbitals and then put a second line on each orbital for a total of 10 electrons. To denote the spin on each electron, put a small arrowhead on the top of one line and the bottom of the other line for each orbital. This can be read as "spin up" or "spin down" since no two electrons can be exactly the same. This is how to fill the d subshell.