Avoid "petsmart" types of places like the plague.
I've seen them sell 20 tangs to a guy as he was buying his first glass (125 gal). Needless to say he had $600+ worth of floaters in no time.
He was telling the guys at a real fish shop what the petsmart ppl did (he had no clue it was a bad idea), they then gave him some education and explained why that was a failed exercise no matter what.
Best bet is to find a real pet shop (in OC, place like the Zoo at El Toro & I-5, Fish 2000 in Tustin etc...) those guys are a resource.
I never do water changes, if you keep the ecology good then you can avoid that shock. I just replace evaporation.
Biggest thing is patience in salts, and some basic knowledge.
...and a tube of Paragon if they get diseased!
