If you're in the northern hemisphere, the north wall doesn't need to be transparent. In fact, making that wall solid and insulating it, then adding some kind of thermal mass, will help even out the temperature inside.
(In the southern hemisphere, it's the south wall.)
As for how far down the glass needs to go, I think that's more situation-dependent. If it's easier for you to make it transparent all the way to the ground, go for it. Personally, I like having the bottom shady so I can use it for storage space, and so wildlife is less likely to run into the walls. (Currently I have a greenhouse that is clear all the way to the ground. In the summer we frequently get
rabbits trapped in there, because the door is open for ventilation, and they don't realize they can't go out through the sides.)
It also depends on how far from the equator you are, if you plan on using it in winter. When the sun is low, you might get more light through the sides than through the top.
Generally though, it's only the leaves that need sunlight, not the pots. So if it's easier for you to limit the transparent parts, just make sure you're not shading the leaves.