ok. first thing is first, whether you are doing a sorority or a community tank, it is HIGHLY HIGHLY recommended that you cycle your tank before getting any fish
why is this?
with an uncycled tank, you will need to do atleast a 100% water change every week.
for a 10 gallon, that is a heck of a lot of water to change. I wouldn't leave it for your poor grandparents to do it for you either.
Look in to tank cycling. cycle the tank first, then begin stocking....
after your tank is cycled you can then do a weekly 25-30% change instead.
and to cycle a tank, you will need a filter.