So, to make your jelly, here is what you will need...

2 heaping cups of fresh dandelion petals (see note below - you'll need to gather about 4 cups whole flowers)

2 C boiling water

1/4 C well-strained, clear lemon juice

4 C sugar

3 oz liquid pectin (I've used SureJell and also Certo...both work well)

yellow food coloring (optional)

NOTE: Look for fully opened flowers, the bigger the better, for ease of preparation. Of course do NOT use any dandelions that have been sprayed with fertilizers or pesticides!

Once you have picked all your flowers (I made sure I just got the heads of the flowers, no stems) you will need to cut off the petals only. You will get some green in there...just hold the flower by the base and snip off the yellow petals. 

When you are done, you will have a nice fluffy bowl of yellow softness. :) Measure out 2 heaping cups of petals and pour the 2 C. of boiling water over them. Let them steep and infuse. You can let them sit for up to 24 hours but be sure to refrigerate if you are not using them right away. I let mine go until the water was room temperature, about 2 hours.
So, now that you have steeped your petals, strain them. I first strained them through a strainer to get the big pieces of petals separated and then put a coffee filter in my strainer to get the itsy bitsy pieces separated from the water. You are NOT using the petals, just the liquid.
To make the jelly, stir lemon juice (I have used lime also and it worked quite nicely!) and sugar into reserved infusion in a two-quart nonreactive or stainless steel pan. Bring to a full rolling boil that cannot be stirred down. Add the liquid pectin and continue to boil two minutes, skimming any foam that may rise to the surface. At this time, you can add up to 20 drops of yellow food coloring. This is done because the actual infusion is a brownish color and because you are making DANDELION jelly, having your jelly look yellow just makes sense. I added the coloring and it made my jelly VERY pretty. :)
While you are cooking your jelly, this is a good time to prepare your jars. Place jars and lids on rack in pan or stockpot deep enough to cover them with about two inches of water, bring to a boil, then reduce heat to a simmer, keeping the jars hot until ready to fill. I didn't have a rack to use so I just put a dishtowel in the bottom of my stock pot and that worked just as good.
Ladle quickly into jars to within about 1/8 inch from the top; clean each rim and threads of the jar as it's filled, and place flat lid and ring on each before filling the next. Screw band on tightly and invert jar on tea towel for about five to 10 minutes. Jars should seal and lids should pop shut within 10 minutes as they cool (I could actually hear mine popping). If they do not seal, you can place them in a hot water bath for 10 minutes or place in the refrigerator. Sealed jars will last up to one year in a cool, dry place and any unsealed jars can be kept in the refrigerator for up to 3 weeks.