Making sour cream from real cream is so easy you could almost do it in your sleep.
Here is how simple the process is:
First, fill a quart jar with cream.
Add 1/8 teaspoon of mesophilic starter. (I get all my starters from www.TheCheeseMaker.com)
Shake the jar and then let it sit on the counter for 18 to 24 hours (this is the part where you really will be sleeping while making the sour cream).
Put the jar in the refrigerator to cool and firm up.