right mate
guppies easiest
platys next
mollies last
havent tried swords yet or others
set you tank up and make sure its totally cycled and ready provide big and small plants but get some thick stuff, (so that the fry can dive into before the mum eats them)
get your fish, (read all the other articles about getting good fish)
2 females to 1 male or the females will be stressed then you'll see problems with the fry
get a good varyed food not just flakes all the time - good food = good fry
sand gravel doesn't really matter, just make sure you clean it well and do your corrct ater changes
then really wait and you should get fry esp from guppies and platys mollies usually require specific water to breed 100%.
as for the fry either leave them in the tank to survice, by a breeder trap and let them grow a bit say 3 weeks in there then relaease them back into the tank , or lastly buy a breeding tank like i did
and soon enough yull think that was so easy, then think about what your going to do with them all
maybe your lfs buys them, mine does in the uk, once they are bigger than an inch and have some colour for a third of selling price cash or trade
hope this helps as this is my personal opinions and not gospal but hasnt hurt me in any way shape or form
lol