#2: Buy a wheel and chewy things for them.
#3: Give them cardboard to chew. (prefferably no ink, but I give my gerbils cardboard tissue boxes all the time and nothing happens)
#4: Try to get more than one, but make sure they are realated, or they were already living together when you first got them.
#5: Females are less known to fight amongst themselves, but males are alright too.
#6: Make sure they have lots of stimulation.
#7: Obviously, give them food. Do not give them treats regularly.
#8: It's alright to bury their food if you want, some owners do this to give them extra stimulation.
#9: Put some tissue paper in their cage, because they like to use it tot build nests.
#10: Oh, and don't forget water...put it in any rodent water bottle. You could put it in a dish, but it spills and some gerbils don't understand the concept.