Check the seed packet for it will have invaluable information, such as how early to start indoors & days to germination. The last "official" frost date is May 20th in our zone.
We are starting Sweet Peppers, which have a germination of 10-21 days, at soil temps of 75-85 degrees. Yes, that is soil temp which means you have to warm the potting mix up to 75-85 degrees to ensure germination. The easiest way to do so is with a heating mat.
Pepper seed need only be planted 1/4" deep in the moist potting mix, once planted, place on heating mat or warmest spot in house, seeds do not need light to germinate. Immediately upon germination light will need to be provided.
If your seeding trays do not have a plastic domed cover, a thin plastic bag (dry cleaning bags) over the top of the tray will suffice. Covering the tray provides humidity which aids in keeping the potting mix moist. Keep the mix moist but not wet and if needed always bottom water.to be continued.......