Here are some links, written just for persians, that might help you. Many people, myself included, have had cats give birth and might be able to answer any other questions you might have. Don't hesitate to ask. It's better to be overly curious than under prepared.
Persian-Cats.com | Breeding | Birthing Time Tips
Persian-Cats.com | Breeding | How to Prepare a Birthing Box
Persian-Cats.com | Breeding | What Are The Stages Of Kitten Development?
Persian-Cats.com | Breeding | After the Birth: Moving & Weaning
Caring for the Pregnant Persian Cat | Divine Caroline
And some links that apply to all cats.
The Stages of Feline Labor - When Your Cat Gives Birth
CatHelp-Online :: Kitten Care 4: Feline Pregnancy and Delivery
Birth Difficulties Symptoms - Cats | petMD
Now, for a few general tips for pregnant cats and new mothers.
- It would not be a bad idea to feed her kitten food during her pregnancy and while she's nursing. Kitten food has more nutrients that the kittens need. As long as they are dependent on their mother, the best way to get them those nutrients is by feeding them to her.
- Set up a birthing box, and more than one if possible, in secluded areas that she likes to frequent. Line it with newspaper or towels that she can shred and nest in. Newspaper actually works better because she can shred it and pile it however you want, and you can just throw it away after the birth.
- It is common for cats to stop labor if they feel threatened or otherwise unsafe. It can last up to a full day, and is no cause for concern as long as she isn't showing signs of distress. Because of that, you'll want to leave her alone during labor unless she makes it clear she wants your company.
- The commonly sited rule is that you're supposed to avoid being around her while she gives birth. That isn't always true. Many cats will go off and find a hidden place to give birth, and they shouldn't be bothered. Some cats actually want their humans around, and will choose a birthing place that is more open and nearby. Basically, just let her pick her spot and use that to gauge what she wants and needs. The more secluded and hidden, the less interaction you should give.
- Cats almost always give birth at night. You may not even know it's happened until a day or two later. If she suddenly disappears, don't panic. Mother cats only leave their kittens long enough for trips to the litter box and food/water dish for the first several days. If you suddenly don't see her for a day or two, she might be hidding somewhere with her kittens.
- Do not move the kittens. Mother cats will almost always put their babies somewhere they feel is safe. As long as you know where they are and can check on them to make sure they're healthy and growing during the first couple weeks, the only time you should move them is if the location is unsafe.
- Find a way to block off underneath appliances and furniture. As soon as the kittens are mobile, they will climb under them. A kitten that crawls under the stove or gets into the lining underneath furniture is more likely to be injured or killed. Something as simple as a rolled up towel will work just fine.
- At about four weeks, start providing the kittens with their own food and water dishes. Saucers work best, so they can reach the contents without straining. Put them next to their mom's, because they will learn by example. Don't expect them to really eat or drink much at first, and don't be upset if mom eats their food. They really just need the chance to explore it. Dry food will be too hard for them to chew, so you can add a little bit of water to it to make a mush.
- Do something similar with a litter box. They'll need a low pan that they can get in without having to climb or jump. Put just enough litter in it to cover the bottom, and put it next to mom's. Don't expect them to use it at first, and don't be upset if you see them eating some of the litter. Just like toddlers, everything goes in their mouth to see if it's food. Check several times a day and clean out any mess that might be in it, and replace the litter daily, to make sure it's always as clean and safe as possible for exploration.
- After she gives birth, mom won't want to leave the babies for very long. Make sure her food, water, and litter box are nearby. Put the food and water as close as possible, since she'll need them more often. The litter box just needs to be in the same room, or possibly a neighboring room.