A system update will probably overwrite a few of your Hackintosh's drivers.
After installing the combo update, you'll need to reinstall these drivers.
The official page from Apple tends to be the first search result.
Alternatively, you can find a link to the combo update on tonymacx86-- the news post for each system update includes a download link to the combo update. NOTE: Another advantage of a combo update is that it allows you to skip intermediary updates.
As the community learns more about a particular system update, this news post will list all relevant information about the update in a convenient and sequential manner. However, there are always exceptions-- for instance, the OS X 10.8.2 update broke a hardware monitoring kext that caused certain Hackintoshes to become unbootable.
As I skipped Sierra I didn’t know about that change though and had to spend some time Googling around before finding the solution.
The first method is to update your computer directly through the Mac App Store.
However, this method is generally not recommended, as it doesn't give you a large measure of control over the updating process.
Here’s a quick reminder of the specs I’m running: Right out of the gate I ran into my first problem: the App Store wasn’t letting me download the High Sierra installer.
The error shown read something along the lines of: “This version of mac OS 10.12 cannot be installed on this computer”.