Starter depends on the spores in the air at your location, which is why bread varies from town to town, country to country, and places that tranfer part of their "mother" have to continually re-supply remote locations or the strain changes.

Just make bread dough and keep part of the unbaked dough as your "mother." Some say divide out part before salt is added.

Edit: http://www.baking911.com/bread/starters101howto.htm