There are many qualities you want your shop to have. First of all it should look and smell clean. No grime or anything on the floor. There should also be an autoclave somewhere in the shop, preferably in it's own bio-room. The autoclave should never be in a room where piercing or tattooing takes place. Furthermore the autoclave should be spore tested every month at least, and the shop should have certificates to verify that it passed. You also want to make sure your artist uses a new, sterile needle, and uses ink from disposable cups. Your artist should also make you feel comfortable; s/he shouldn't intimidate you or give you a bad attitude.
As for research, ask around your town. Often the best way to find the good studios is to ask those with mod experience. Once you find a potential artist, make sure the above requirements are met, then take a look at her/his portfolio. You should like his work, if you don't find another artist.
And remember, go with your feelings. If you feel that something is wrong with the shop, walk out. Your safety is king hun. It is THE most important thing in your whole tattooing experience.