@StankyDanky Welcome to AFN
When people use the Jiffy peat pellets there are two common mistakes they make the first is not adjusting the PH up. Peat is naturally acidic and this can limit root development. Soak your peat pellets in PH 6.4 water before planting in them. The second mistake is not watering the pot they are transplanted into completely. A lot of new growers water in a little circle around the plant. This stunts root growth.
What you need to learn about watering will come with practice. Here are the basic rules: Never let the soil dry out. Soil and or coco can become hydrophobic if allowed to dry. This means it repels water. This in turn will create dry pockets in the soil and the roots and microbes will die there. If your soil - coco have accidentally dried out use a surfactant to help re-wet it. I like yucca powder. Don't let soil remain soggy by watering too much too often. Root rot, damping off, molds, fungus gnats and other problems start in soggy soil. When you do water
water the entire pot. How to learn when to water starts before you plant the seed. Fill your container with fresh soil/coco and weigh it (heft it) this is the lightest weight and consider it a dry pot. Now slowly water until the soil/coco will no longer absorb the water and run-off begins; weigh the pot (heft it) this is the maximum water, the wettest the pot can get. The difference between wettest and driest is the maximum water weight, for ease of explanation lets just say the water weighs 20 pounds. When the pot loses 10 pounds
(half of the water weight) it is time to water again. There is an art to watering.
on your next grow!