I'm often asked how often one should shave their head.
I can't really offer a specific recommendation. After all, it's really a matter of personal choice: how smooth you want your scalp to be, how sensitive your skin is, and how much work you want to put in.
I've communicated with people who only shave once a week, people who shave a couple of times a week (like me, usually once every 2 or 3 days), those who shave daily, and a select few who actually shave more than once per day. Each choice has its advantages and disadvantages.
Personally, I like shaving every 2nd day. After the 2nd day, the stubble's a bit much for me. But I don't really want to shave every day, as it gets a bit tiresome.
But a good rule of thumb is that you'll probably want to shave your scalp about as often as you normally shave your face. The hair tends to grow at the same rate, so you already have some idea of how much stubble to expect.