writing the electron configuration for the pairs
Na+1 ion and the Ne atom

O-2 ion and Mg+2 ion

(I don't know the level of your chemistry background, so don't take offense if you know much of this, but hopefully I won't be starting too advanced).

The first step is to figure out how many electrons the atoms or ions have. For an atom, the number of electrons will be equal to the number of protons. This is called the atomic number. If you don't know it, it can be found on a periodic table, such as this one. The atomic number is the one in the upper right of the square. For ions, subtract one electron for each positive charge or add an electron for each negative charge.

Electrons go for the lowest enegy level first. This page shows you the order of the energy levels. Just fill in the blocks as they do in the examples on the page.

For ions, subtract one electron for each positive charge or add an electron for each negative charge.

To clarify that (as I have been asked to) Na¹⁺ would have 1 more positive charge than negative charges. Since Na must have 11 protons, this would mean it has 10 electrons. Filling in the orbitals this way gives you:
1s² 2s² 2p⁶

Similarly, O^2- would have 2 extra negative charges. Since O has 8 protons, this gives it 10 electrons.
Filling in the orbitals, this also gives you:
1s² 2s² 2p⁶