David mentioned MILES stars. I find a good way of checking the quality of ones observations is to measure a few of these stars and compare the results directly with the spectra as measured professionally. Any differences can then be investigated and once they are close to the professional version one can confidently submit spectra of other targets to the BAA database for example. You can see an example of this sort of test here using the ALPY 600.
and there are more examples and further information here on my website