How do I get an object to ensure it is perfectly in line with the x, y and the z axes? I created this object by creating an ico sphere (for the main body) and cylinders (for the legs and eyes).  When I joined everything together it is showing a different number for the rotation on the y axis.

How do I ensure that the entire object is perfectly in line with the x, y and the z axis?

Yes I know I could just press Ctrl + A  and then click on rotation to set its current rotation as 0, but what if while I was constructing this I have accidentally rotated a tiny bit?



As shown in the 2nd image, specifically where I have circled and selected the current vertex, I know that this is the center of the front face. I want to use this point to determine if it is point completely straight along the y axis, how do I do that?
My guess is that you joined one of the legs as the final active selection. The final active selection becomes the new origin (and orientation) for the combined objects. The left middle leg looks like it's rotated 48 degrees on Y. Start again, select the body last. If you have accidentally moved it in the process, AltR, AltG will set it back in place.