Is there some kind of map to show what grid point is what?

Like i have regions at 1000 1001 and at 1000 1002. I dont understand how to find out where say 1010 1010 would be

Actually these are X,Y Co-Ordinates. So the South West most point is 0,0.

So the co-ordinate 1010,1010 will be North East of your listed co-ordinates.

Example a Cube.

1000,1001     |         1001,1001

1000,1000     |         1001,1000

X +> (across),   y +^ (up).

I made mine upside down for those down under