The Procedure
You need to put the Lima beans into water overnight--don't forget this (translation: I always do). If you do, you can still boil them twenty minutes before beginning to cook, but they will not have such a nice aspect (their skin will be wrinkly).
Heat olive oil to medium-high temperature,so it barely covers the bottom of the pan. Excess of oil makes the course pretty heavy on the stomach. The best adviser is experience. Remember that oil usually spreads out as it warms up, so be conservative.
Clean the chicken and rabbit, try and remove as much fat as possible (I think the average American chicken is rather disgusting in this respect), but unless you really dislike it, leave the chicken's skin--it gives a nice flavor to the course. Salt and start frying the chicken and rabbit.
Meanwhile, wash the vegetables and split all green beans. Dice the tomatoes into tiny pieces: you should not see any tomato chunk in a paella serving. Alternatively, you can use a grater. Do get rid of the skin in any case. Salt the vegetables and turn the chicken/rabbit over.
Prepare a recipient with fresh water, 125cc per person, and keep it aside.
When the meat is golden, take it out and set aside. It actually does not matter if you do not do it, but it facilitates the roasting of the vegetables. Paella pans in Valencia are quite wide and slightly concave on the inside, so we move the chicken to the periphery and cook the vegetables in the center.
Drop the green beans and the Lima beans into the oil and fry them for about five minutes, stirring occasionally. (Make sure the Lima beans are dry or you'll get some unexpected "fireworks.") Then add the paprika and stir again. Fry for about half a minute and then add the tomato. If you fry the paprika for too long you will ruin it. The water the tomato contains will cool down the oil enough to "protect" the paprika for a bit. Stir for a minute, then add the meat back into the pan and mix everything. Next, add the water.
Use a wooden stick to touch the bottom of the pan and measure the height of the water. You will need it later. We do not need such a stick in Valencia, since the handles of our paella pan show on the inside, to indicate where the water is supposed to reach (there are different pan sizes for different number of guests; some people have quite a collection!).
Let the water boil at moderate heat for twenty minutes. Then take the pan away from the burner--but don't turn the burner off. Add water until you get back to the original height: use the wooden stick for this delicate operation. Then put the pan back on the burner. Add salt and let it boil.
As soon as it starts boiling, use a spoon to taste the water. It is important to take the water from the bubbles: it's the only part of the water's surface with no oil. Taste for salt. Add salt if necessary, but don't be slow on this: you want to add the rice before too much water evaporates. When done with the salt, add the saffron. You may add the saffron strands (or powder) directly, or you may boil the saffron in a bit of water and then pour that water into the paella, discarding the saffron strands.
Next, add the rice, 100cc per person. Remember that you want to keep it shallow, 7-8cm. Shake the pan slightly to spread the rice, and wait until the water boils again. Then, lower heat to minimum and cover, and let it simmer for 25 minutes. If you have used the same type of rice and quantities, I can guarantee it will come out perfect most of the time. Note that this is not the way it is done in a paella pan. In that case, the paella pan is open, and the amount of water is correspondingly higher, about two to three times the volume of rice. This method is less "fool-proof" however, so I recommend that you stick to Kokuho rice guidelines.
During the last ten minutes of simmering, quickly add a couple pieces of rosemary on top of the rice and cover again. The steam will activate the scent of the rosemary, which will bathe the paella.
At this point the paella is almost ready: Simply take it out of the range and cover it for a couple minutes to concentrate the rosemary scent, and maybe soften a few rebel grains of rice.