hey there
in reality it up to you
you can either go with fishless cycling which can be found here:
http

/www.fishforums.net/index.php?showtopic=113861
this method sees you substituting teh fish waste [which is ammonia] with actual ammonia from a bottle to get the filter ready and going through the nitrogen cycle
this is a brief picture on the nitrogen cycle
http

/www.angelsplus.com/images/NitrogenCycle_small.gif
fishless cycle can be a very long process sometimes lasting up to 2 months [and i know the fluval edge is an expensive piece of kit just to sit around and have nothing in it!]
or you can go whats known as fish in cycle where you add fish [instead of pure bottled ammonia] and do water changes to stop the buildup of ammonia that they will be producing, as ammonia can poison fish which is why it is suggested to do fishless as you can somtimes lose fish in the initial stages, if you choose the latter then you need to be vigilant with water changes [i personally did fish in and didnt lose any fish, and that was a year ago]
what i do suggest is that you get a wate test kit such as the api feshwater master test kit or take some water to your fish store and have them test it, but for ease buy your own! the undisireable levels to have is ammonia above 0 nitrItes above 0 nitrAtes are fine in levels 0-40 [thereabouts] they are taken out with water changes or eaten up by live plants [as the picture states]
now i know its a lot to take in, but were here to help [most...] if you have any questions make a thread here or you can email me [its on my profile page, as you cant pm untill you have made 30 posts]
anyways on to the fish...its true neons are delicate and I would wait until at least the 3-4 month mark, things you could look at are shrimps [again put them in later] snails, pygmy corydoras or panda coydoras, galaxy rasboras [also known as celectial pearl danios] rasbora brigittae, you could even look at getting a lone male siamese fighter, it would look great having him and some pygmy corys and shrimp in it =]
but again everythign is up to you, its all trial and error, you soon learn things sometimes the hard way