go slowwwwwwwwwwwww. i would do some research on what fish you like, find one to be a center piece fish (ie an angel or tang) and build up your tank around it with compatiable fish. put in the least aggressive fish first, then slowly add you other fish, weeks or even months later (esp if the fish need a mature tank) patience is key, believe me. hth and good luck with the new tank!