Don't worry about asking me questions ever. I love to help people, and don't get bothered in the slightest when people ask tons of questions. Ask away!
Now, with that said....
Depending on what colors you get from the LFS, you'll get decent fry. Guppies aren't really like Bettas in the breeding sense. Most Guppies you get at the LFS are decent. None of them are really pure, mind you, so you might get some mutts, but they all turn out well. You might get a mix of red and blue, with some funky markings. You won't get designer show Guppies, I'll tell you that, but you'll get average Guppies.

I
'd personally put the female in a 10 gallon. Breeding traps and breeding nets can be stressful for them, so it can cause them to abort, miscarry, have birthing troubles, sometimes even a die. A 10 gallon will be heaven for her.
For your tank, you could either get a male and 3 females, or 2 males 6 females. I'd personally go three females per male, since that's a smallish tank and less room to get away.
Anyway, onto the fry tank. I'm assuming that's what you mean by putting the female in the 10 gallon? Let her have fry there and raise them seperately?
For substrate, you basically have three:
- Sand. This is a fairly easy option. It's good because it's very safe for fry. And also, most of the waste will stay on the top of the sand, so it's easy to syphon off. However, you do need to stir the sand, but that's easy to do with the water changes.

- Bare-bottom This is another pretty easy option. All the waste is easy to see, and you don't have to worry about any substrate at all. However, you could only really have fry in this tank, no Cories or bottom-dwellers, but that's usually not a problem in a fry tank anyway!
- Gravel. Gravel is also fairly easy, though probably the hardest of the three. For two reasons. One - Sometimes fry can get stuck between pieces of gravel. And Two - Little bits of food and waste can fall between the pieces of gravel, which makes it harder to clean out, and you can miss some, which will deteriorate your water quality which isn't good for fry! It is pretty easy to syphon though, because you don't have to worry about it getting sucked up like sand.
So that's basically your substrate options. For decor, anything is good...rocks, wood, plants, little caves...basically anything that gives the fry something to hide in, and chase their brothers and sisters around.
Another thing with fry, is they need good water quality. I'd recommend you do at least twice a week water changes, but often is better. You can even do it once a day. Whcih brings me to water changes. They can be kind of hard with fry, because you're always worried about sucking them up and everything. There are 4 ways you can do it, or you can combine some together.
- Make a little syphon out or airline tubing. This usually works pretty well, because it's too small for fry, but it still gets most of the waste.
- Use a turkey baster.
- Shine a flashlight near the tank, but not in it. Most fry will eitehr go towards it, or away from it, and then you can clean where they aren't.
- Just syphon or do water changes as usual. Just check before you dump the water, that no fry are there. If some get syphoned up, it's not going to kill them. Just stick them back in the tank.

Now, for feeding. It's best if you can feed at least 3 times a day, preferably 5-6.
Guppy fry are born pretty small, you may want to start with Liquifry. Or you could just skip to some kind of fry food, like Hikari First Bites, or Tetramin fry food. This you can feed for about two weeks, maybe longer. You can also alternate in Live Baby Brine Shrimp.
When they get older, you can move on to finely crushed flakes. Remember to make them reeeeeeally small pieces! You can continue feeding the Brine Shrimp here if you want.
As they get even older, the flake pieces can get older, and you can start giving them little pieces of Freeze-dried/Frozen foods. Small things like Daphnia, or very finely crushed Freeze-dried Brine Shrimp works well. Don't feed this more then maybe 2-3 times a week, because too much can cause bloating and/or constipation.
And as they get even older, you can start feeding things in bigger pieces, and other bigger foods until they are basically eating what the adults are.
They are safe to put it with the other fish when they are too big to fit in the biggest fish's mouth. However, it would be best if you could seperate brothers and sisters to prevent too much inbreeding. If it happens, it happens. One or two generations won't hurt too much, but it's betetr if you can seperate them. Females will have tiny gravid spots, and males of course will get gonopodiums. Be aware, males can look like females for a long time, then one day get a gonopodium. So just remember that!
Another thing to remember, is Guppies have fry often. Females will produce fry about every month. If you have a small fry tank, you can't raise all these fry. Pace yourself. As you get more and more fry, you can always do a survival of the fittest, though I know it sounds mean. If you do this, just feed the tank as normal, and the fry will figure out a way to eat. Also, remember, even if you seperate the male from the female, once they female has been impregnanted once, they can store sperm for up to 7 more pregnancies! Basically, they can have 7 more batches of fry, with no contact with a male.
*Has a feeling she should stop rambling before William's head explodes with information...*
Best of luck!
