Place 2 Tbsp of salt in the bottom of a sterilized jar.
One by one, prepare the lemons in the following way. Cut off any protruding stems from the lemons, and cut 1/4 inch off the tip of each lemon. Cut the lemons as if you were going to cut them in half lengthwize, starting from the tip, but do not cut all the way. Keep the lemon attached at the base. Make another cut in a similar manner, so now the lemon is quartered, but again, attached at the base.
Pry the lemons open and generously sprinkle salt all over the insides and outsides of the lemons. (photo example: http://www.elise.com/recipes/archives/001815how_to_make_preserved_lemons.php.
Pack the lemons in the jar, squishing them down so that juice is extracted and the lemon juice rises to the top of the jar. Fill up the jar with lemons, make sure the top is covered with lemon juice. Add more fresh squeezed lemon juice if necessary. Top with a couple tablespoons of salt.
Seal the jar and let sit at room temperature for a couple days. Turn the jar upside down ocassionally. Put in refrigerator and let sit, again turning upside down ocassionally, for at least 3 weeks, until lemon rinds soften.
To use, remove a lemon from the jar and rinse thoroughly in water to remove salt. Discard seeds before using. Discard the pulp before using, if desired.
Store in refrigerator for up to 6 months.
You can add spices to the lemons for preserving - cloves, coriander seeds, peppercorns, cinnamon stick, bay leaf.