There are several formulas for hop extraction. I'd recommend some brewing software like beersmith to help you figure it all out.
Add all the water to the pot (I use 6 gallons to account for boil off).
Turn on heat and add steeping grains.
Bring temp to 155F +/- turn off heat and wait 20 min +/- then remove steeping grains
Turn heat back on and bring water to a boil.
Turn off heat and add extract
Stir it a whole lot to ensure extract is completely dissolved and will not scorch the on the bottom of the pot
Turn on heat and bring it back to boiling
Start the clock, add hops per the recipe, etc...
If your on a stove top you will soon want a propane jet burner
If you don't have a chiller you will soon want one of those as well.
Reason: forgot to remove the steeping grains