Start peppers 8-10 weeks, and tomatoes 5-7 weeks, before you intend to plant out in the garden
Use a light weight seedling mix, and a shallow tray or pot. Lightly cover seed 1/4" deep, and moisten.
For best germination, keep day soil temperature between 80-90 degrees for peppers, 75-80 degrees for tomatoes. Use heating mats for bottom heat for peppers, not needed for tomatoes. If growing under lights, keep the lights on for 16 hours a day, off 8 hours a day. Allow the soil temp drop to 70-75 degrees at night (when lights go off). Average time for pepper germination is 7 to 21 days. Tomatoes germinate more quickly, within 10 days.
Many varieties of pepper seeds would benefit from using Saltpetre (Potassium Nitrate). Saltpetre softens the seedcoat and is wonderful for difficult to germinate pepper varieties such as Habaneros, Chiltepines and Rocotos, as well as for older seed. Mix 1 teaspoon per quart of warm water. Soak seed for 24-48 hours, and then sow immediately.
A humidity dome or sheet of plastic keeps soil temp and soil moisture consistent, and quickens the process of germination. Avoid letting the soil become saturated. Take off your cover/plastic for at least ten minutes every day. Allow the soil surface to dry slightly between watering, but do not allow the soil to completely dry out.
Once your seedlings emerge, remove the cover/plastic and reduce temps to 65-70 degrees. Move to bright light.
When your seedlings have two sets of true leaves (3rd set of leaves) you can begin to fertilize. Start half-strength at first, gradually increasing strength as the plants grow. Up-pot into a slightly larger pot.
One week before planting your transplants outside, begin to harden them off so that they can handle the sun. Give your plants a few hours of morning sun to start, increasing the time a little more each day. Don’t rush this part. This should take about a week. Try to plant out in the evening, or on a cloudy day.