Socks are probably more important than you might think.
Many of today's professionals go for the longer sock which helps to support and relieve tired muscles.
But there are no fixed rules and short ones are fine. Like the shorts, it's a style thing really.
There are all sorts you can choose from - different lengths, different colours, different materials.
You've heard it before but the main thing to consider is comfort.
Your feet work incredibly hard in basketball and they deserve nothing but your care and attention.
Blisters can be a horrible problem - particularly if you play long games - so aim for the socks to be quite thick and soft.