Congratulations! You are the proud new owner of your own personal fermentation!
Step 1: Give it a name!
Step 2: Keep it in the fridge...left out on the counter it will pop the top right off and ooze all over your countertops
Step 3: Feed it only yummy organic unbleached flour. You can use rye, but it's used to unbleached white. Use room temp water. If your tap water is nasty, use bottled.
Step 4: When you are planning on using it, pull it out the night before, scoop out about a TBS of the starter and put it in a bowl, add equal parts quality flour and water. Cover with saran wrap.
Step 5: This starter takes about 7-9 hours to peak depending on the ambient temp of your house. If it's cold, stick the covered bowl in the oven and turn the oven light on. Or stick a mug of hot water in your microwave and put the bowl of starter next to it.
You'll know when it's ready because it'll be all bubbly and happy. You can even take a little bit out and see if it floats in water.
Find a recipe and have fun!