Start by blanching tomatoes. To do this, heat 2 quarts of water in a 4 quart pot to boiling. Working in batches, dip tomatoes in boiling water fro about 60 seconds, until the skins begin to split. Remove from water, and rinse with cold water.
Slip blanched skins from tomatoes, and core, and roughly chop them.
Finely dice celery, onion, and pepper.
Add tomatoes and vegetables to a large pot with sugar and salt.
Bring to a simmer over medium heat, stirring occasionally, and simmer for 20 minutes.
While tomatoes are simmering, prepare canning supplies by filling canner with warm or hot water, and sanitizing jars and lids, etc.
Fill jars with stewed tomatoes, leaving about 1/2 inch headspace.
Add 1 tablespoon of lemon juice to each pint.
Wipe rims of jars with a soft cloth to remove debris.
Screw down lids and bands firmly.
Arrange jars in canner so that they’re not touching each other, or the sides of the canner, and bring to a full rolling boil.
Process pints for 40 minutes, or quarts for 45 minutes.
Remove from heat, and let cool.
After jars are cooled, remove from canner.
Check seals after about 24 hours, and store in a cool place out of direct light.