Before use, feed the starter. Transfer 50g of the starter to a large jar. Add 40g rye flour, 40g whole wheat flour, and 80g water. If you don't have rye flour, you can use 80g whole wheat flour instead, but sourdough starters seem to love rye! Stir well. Make sure there is enough room in the jar to allow for the starter to triple in size. Leave the jar with the lid loosely on at room temperature or somewhere warm. In a couple hours, the starter should have doubled in size with bubbles in the mixture. If it hasn't, give it another feeding, repeating the process.
You can also feed the leftover sourdough starter and stick it in the fridge after it doubles in size so you have a continous supply of sourdough starter. Once in the fridge, feed the starter once every week or two to maintain it.
For the recipe below, you only need to use about half the amount of starter and feed the leftover for future bread making.
Sourdough Bread Recipe (77% hydration):
Ingredients (for 1 loaf):
100g Starter (fed and active -- feed the starter just before going to bed and start the recipe the next morning)