thats more than enough for any guppy. guppys will breed in most any atmosphere, and will do fine in almost any numbers. you can really experiment with them since theyre so tolerant of eachother and are low waste producers in general. dont be affraid to add a few extra if you want. however like any fish make sure the diet and water are good. guppys dont require space like say a convict might but they also have their needs even if they are less
If they are live plants then all sorts of timy animals (infusoria) will live on and around them, such as rotifers, and ciliates. The babies will feed on these, and on foor dropping from the parent fish. Lots of live plants make raising fry very easy by providing cover and food. Guppies are already easy, but it can't hurt.
No work, if you keep live plants, and enough of them, it is already there. Tanks with live plants are not static, things are alway in motion, life is living, dying, breeding, all in your live plant tank, and you don't even know it.
A mature female guppy will always be gravid (pregnant). You can tell by the swelling and black spot near the anal fin. Poeciliids store sperm in there body, and will use it, there for minutes after giving birth they fertilize another batch. The gestation period should be about 2 weeks, and will yield about 12 or more fry.
At first, it will seem like its taking fooorevaaar to get the babies going, but one morning you are going to wake up and your tank will be filled with them. In my 45, I bought 5 guppies. Four months later it was solid fry.
I hope you know that in your 10 gallon, you are going to need to remove fry after a while, other wise your tank will crash. I had a 10 gallon guppy colony, it got up to about 200 guppies (mostly small) and I couldn't bring myself to feed them to the other fish. One morning they were all dead.