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i can tell you how to make mesophelic and thermophelic cultures from yogurt and buttermilk
Bacterial cultures are the key to cheese making. Almost all cheese needs to have some sort of bacterial culture added to it. These bacterial cultures not only give the cheese its flavor, but also acidify the milk, which aids in the coagulation of the curds. Examples of cheese that can be made without cultures are Queso Blanco and Ricotta. These are acid precipitated cheeses, and are quite bland. It is the bacteria consuming the lactose (milk sugar) in the milk and excreting lactic acid that acidifies, or ripens the cheese. This ripening is the basis of the long-term keeping quality of cheese.

Basically, there are two types of cultures: thermophilic (heat loving) and mesophilic (moderate temperature loving). There are also many variations on these cultures, such as goat cheese mesophilic and fresh cheese mesophilic. Each culture will give the cheese a different flavor, but the handling and preparation of the cultures is the same. [COLOR=""Red""]Buttermilk is a mesophilic culture [/COLOR]and can be used as such. [COLOR=""Red""]Yogurt is a thermophilic culture [/COLOR]and can be used to make cheese that calls for a thermophilic culture.

I have this book. It goes into agreater detail on making the home made cultures. Simple actually :)
http://www.thecheesemaker.com/home_cheese_making_book.htm

there are quite a few good cheese books"