This is how the starter looked after a vigorous stirring today. A little sluggish, probably because it hasn't been fed in a day. But it is more or less ready to use, and all I have to do now is maintain it.
Maintaining Your Sourdough Starter:
If you keep your starter at room temperature, feed it daily.
If you keep your starter in the fridge, you can feed it once a week.
Be sure to store your starter in a large enough container, for a healthy starter can double in volume after feeding. On that note, don't store starter in a completely airtight container.
To feed your starter, first pour out and discard one cup of starter. Then add 1 cup each of water and flour. You might add a bit more water than flour, if desired. Stir vigorously after each feeding.