Happy Chooks,
I've only used Meyer Lemons; you may have to adjust if using other lemons but the recipe is about the same for orange or other citrus. My recipe is an amalgam of several I found online. Check out the center for home food processing at UGA. It's great on biscuits or toast, makes a good base for lemon vinagraite, or lemon slaw. So a base for glaze for seafood.
1.5 lbs of Meyer lemons sliced very thinly, seeds and pithy center removed and set aside. (That's 5 - 7 Meyer lemons.)
4 cups water
4 cups sugar
Put seeds, ends removed from lemons, and pith in cheesecloth and tie closed with twine. Put pith bundle, lemons, and water in nonreactive pot. Bring to a boil and reduce to a steady simmer. Simmer until peels are just tender - 30 to 45 minutes.
Remove pith bundle and allow bundle to cool just until you can handle it. Squeeze bundle, scraping "goo" from it into lemons along with any juice you squeeze out.. The goo is pectin. This is a lot easier than it sounds.
Add the sugar and bring to a rolling boil. Boil until it reaches 220F. If no thermometer do the plate test (a drop on a frozen plate should "set" and if pushed with fingernail surface of drop should ripple.)
Fill prepared jars leaving 1/4 inch headspace and process in boiling water bath for 10 minutes.