Paneer can be made out of whatever milk is available and adding gradually just enough curdling agent until the curds separate and the whey is clear, but for beginners though, here are some measurements from the cookbook by Adiraja prabhu:
INGREDIENTS:
10 cups (2.3 ltr) whole milk
5 tablespoon lemon juice or 2 teaspoon citric acid,
or 1 1/4 cups (300 ml) yogurt, or 2 1/2 cups (600 ml) whey
(There are many options. Use whatever is on hand to curdle the milk. Bottled lemon juice, fresh lemon juice, and yogurt whey also work well.)
Each curdling agent will give slightly different effects to the finished cheese.
PREPARATION:
1. Bring the milk to a boil.
2. Add the curdling agent and stir. It is crucial to pour it in at the rise of the first boil, not after it is turned off and cooling down. Almost immediately the curds and whey will separate. If the whey is not clear, add a little more curdling agent. The separated curds and whey will look something like this after the heat is turned off:
3. Separate the curds from the whey through a cheesecloth or a clean piece of thin, undyed, absorbent, and 100% cotton cloth.
LATER NOTE: I currently pour the curds directly into the sieve to drain the whey. Meanwhile, I have a cheesecloth already spread out on a kitchen counter. Under the cheesecloth is an absorbent kitchen towel, so that the remaining whey can have somewhere to go besides the floor. Next, I flip the drained curds from the colander onto the cheesecloth, fold the cloth and then place the cooking pot, this time filled with water, on top of the cheescloth covered curd.
If you want soft paneer, do not press very long. I'd go only 1 minute these days.
You can save the whey for a variety of purposes such as a sweetened beverage or making more paneer. I prefer using it in chapati dough, bread dough and batters or biscuits
Pressed paneer is often cut into chunks for deep frying, stir frying on a skillet or boiling.
Here's a tip for even softer fried paneer. After frying, add it to the veggies while they are cooking. The cooking juices make the paneer even more tender, along with short times of pressing it under a weight before cutting and frying. 
Pictured here is more paneer than vegetables. One has to judge how much to use.
If you need more of a soft, crumbly fresh cheese, called "chenna", while making, for example, scrambled paneer, just hang it up in a cheesecloth or allow it to drain in a colander without pressing. The longer it hangs, however, the dryer it'll be.