I've been reading pages such as this one: http://comp.uark.edu/~jgeabana/blochapps/bloch.html
Which talk about the Bloch sphere, but I've been unable to figure out how to plot states on the sphere due to both states being a complex number, thus resulting in 4 "coordinates".
Many sources say it's only the relative angle between the states that matters, but that seems odd to me, since there is an absolute $|0\rangle$ and $|1\rangle$ state, which makes it think that both imaginary parts of the complex values matter.
So, how would I plot things like these, or at least, how would I convert them to spherical coordinates for plotting on the bloch sphere?
$$1/\sqrt{2}(|0\rangle + |1\rangle)$$ $$1/\sqrt{2}(|0\rangle - |1\rangle)$$ $$1/2(\sqrt{3}|0\rangle + |1\rangle)$$
Using equation (1) of your link, consider your first qubit:
$$\cos\theta/2 = 1/\sqrt 2, \quad e^{i\phi}\sin\theta/2 = 1/\sqrt 2$$
Hence--given the range of values of $\theta$ and $\phi$--we have $\theta = \pi/2$ and $\phi = 0$.
Proceed similarly for the other qubits.
An important thing to remember about qubits is that we don't care about overall phase. Hence if we have a qubit of the form
$$|\psi\rangle = e^{i\alpha}a|0\rangle + e^{i\beta}b|1\rangle = e^{i\alpha} \left( a|0\rangle + e^{i(\beta-\alpha)}b|1\rangle \right) $$
we find the Bloch representation of $a|0\rangle + e^{i(\beta-\alpha)}b|1\rangle $.