It hotkeys exactly like command and conquer. Which is terrible, because a unit can't carry multiple hotkey groups. If you rehotkey a unit, it will lose its previous group.
Control to hotkey, shift clicking will add units to your selection, which you can then rehotkey. Pressing the hotkey will automatically center the unit.
I strongly suggest hotkeying your workers, especially if you're going to prechop/cancel orders.
Let's say you want your first worker to build a road for 1 turn, then cancel orders and move. You have to
1. find the worker
2. left click the worker
3 Right click to move it one tile, press r to road.
Now your worker is automatically deselected and the game moves on to your next unit.
4. So now, find worker again
5. Left click worker
6 Backspace to cancel
If it's at control 1,
you press 1
right click move, press r
1 backspace