Estimate how many quart canning jars you think you will need for the cucumbers you have and prepare a couple extra. Wash the jars in the dishwasher on the hottest water setting.
While the jars are washing, wash and drain the pickling cucumbers. Wash the dill blossom heads or dill sprigs, and shake dry.
Combine the ingredients for the brine in a large stockpot and bring to a boil. When it has boiled, turn off the heat and cover the pot with a lid to keep the brine hot until you need it.
Preheat the oven to 310°F (155°C) and remove all the racks except the bottom one. (Yes, that is the right temperature - not a typo.)
Set the metal canning lids into a saucepan of water and bring to a simmer. Keep hot until you need them.
When the jars have finished washing, set them onto a clean dishtowel on the counter. Into each one place 1 dill seed head, 1 clove of garlic, 1 or 2 bay leaves and 6 peppercorns. Hold the jar sideways, and fill it with cucumbers, packing them in tightly to fit in as many as possible. Larger cucumbers can be cut into quarters lengthwise as 'pickle spears' to make them easier to fit into the jars. Pack the cucumbers so there is an inch (2.5cm) of space between them and the top of the jars.
Bring the brine back up to a boil, then pour it over the cucumbers, covering them completely and leaving ½ to ¾ of an inch (1.5-2 cm) headspace at the tops of the jars. Wipe the rims of the jars with a clean, wet dishcloth. Place one of the hot metal lids on each jar and screw on the metal ring so it is just finger tight (how tight you can turn it with just your thumb and index finger).
Place the jars onto a cookie sheet or in a 9x13" pan (easier to handle) and carefully slide it into the oven. This is the only tricky part since the pan full of jars is awkward and heavy. I only do 4 to 6 jars at a time.
Bake for 10 minutes (15 minutes for 1.5 quart jars).
Carefully remove the jars from the oven, keeping them level as you handle them, and place them right-side-up on a tea towel on the counter. Leave them undisturbed until they cool.
You will notice some bright green spots where the brine hasn't penetrated the pickles totally yet. Don't worry about them - they will be uniformly olive green in colour by the time they are cooled. You should hear a slight pop as each jar seals over the next half hour or so. (Don't be tempted to touch the lids and force the seal to happen.)
Once the jars are cool, check to see that they have sealed by seeing if the slight bulge in the middle of the metal lid is sucked down and the lids are smooth. If you can make the center of the lid move up and down by pressing on it with your finger, it has not sealed. Keep those jars in the refrigerator, wait a week for them to totally pickle, then use up in a couple months (should be no problem to do that). Although, I have never had any jars fail to seal by doing them this way.
Tighten the rings and store the jars in a cool dark spot. They will be ready to eat after one week, though they can take up to a month to fully cure.