The general way to check and align is with a 5 sided square. Indicate the square in to the X axis, then without moving the square, indicate along the Y axis. Then tip square on it's side and check Z in X and Y planes to the table. Usually a test bar goes in the spindle from there to check spindle parallel to the table. Now, a real 5 sided square is WAY too expensive for a hobby machinist to buy, I think our ceramic square was ~10K, but it's square to micro-inches. I would think a good quality 4-5-6 block or something would work well for smaller machines.