the first thing i would do when you get your lens is a focus test. you can download printable "rulers". which you will place at a 45 degree angle. you then will focus on some mid-point on this "ruler" then by seeing which marks are sharpest, you can tell quite easily if its front or back-focusing.
the 2nd test you can run is a resolution test. there are charts and instructions online, you can then compare your results with published tests to see if you measure up.
and finally just do some subjective tests. shoot some scenes in good light with lots of minute details in the center and edges of the frame. and then just take a look, see how it resolves at multiple apertures.