When to refrigerate

1. I would recommend leaving it at room temp and feed for a few more days (maybe 3-4) to give it some rhythm and stabilize it.

2. Give it a couple of hours before you refrigerate it, until it starts showing activity (growth or bubbles).

3. While for a spontaneous bake you can use it right out of the fridge (given it has reached peak maturity), I would recommend feeding it at least once, better twice before using it in a bread. This reactivates it and prepares it for the task to come.

Well done on establishing the starter yourself. I got mine from a cousin who in turn got it from a friend of his ... I keep mine in the fridge the whole time and feed it once or twice a week (it does start to get pretty sour if I only feed it once). When I want to bake I take a dollop (20 - 50 g, depending on the recipe I'm using) of the starter from the jar in the fridge and use it to make a "sponge" (starter + flour + water) that I use as the basis for my bread recipe. I mix up the sponge and leave it to ferment overnight at room temperature, then go on with the next stage of the dough. That seems to work for me ... I'm not as scientific as some ... I just make sure that when I feed the starter I use 50 g of flour and 50 g of water each time. 

If you spend some time reading the posts on here you'll find there a many variations on how to maintain a starter ... 

If you start thinking about your starter,breadmaking and yeast in concepts, it will be much easier to figure out what to do. Liken the situation to something more familiar to your world, say..... baking a loaf of bread is like building a house.

Flour (the gluten part) is like the 2x4's- the skeleton. With wheat flour, it is also the starchy gel part that is like the windows in a house but in bread is the walls of the bubbles.

So what is a starter? Your starter is your building crew! They need to be fed in order to be strong and need a clean place to stay. At first, there may only be a few of them and if you started them working (using a starter that is too young), they probably would only get a few walls built and the house would not be very big. However, if there is enough food and you give them some time, they will make more workers (yeast) and be able to work faster/stronger. When you refrigerate an active starter, most of the workers go to sleep,don't eat (or very little) and aren't active or if left too long-die in their sleep. The survivors will wake up when they are warm and food is provided. Usually plan on 2 feedings to really strengthen them.

But what is the best way to think about how to feed a new starter? When you mix flour and water, there are a few, natural yeast cells present on the wheat granules that you want to cultivate and grow. Think "work crew" again. If 2 workers show up in your bunkhouse, provide food, a good temperature and a clean house. But remember, it is only 2 crew members so you do not have to provide a feast for 100 in order to feed them. So when you first start your starter, mix just a few tablespoons of flour/water (which is enough food for several days), keep warm and just stir until you see bubbles a little bit around the edges. Yay! They are eating and making more yeast/crew to party with! At that point, if you discard, you are throwing away half your new crew members! Just provide a small feeding (flour/water) again and stir. Stir 2-3 times per day. As it becomes more bubbly-that means more and more "crew" are eating. If you see a LOT of bubbles or a rise in the level-that is when you start discarding (you are housekeeping their bunkhouse after a frat party) and feed. Do this twice a day.

Lactos join the party

At some point between the start where there are just a few bubbles and suddenly a lot of bubbles, lactos (a new crew member) has joined the party. They are not heavy lifters and can't raise a whole loaf so don't get fooled of early on if your starter goes crazy. Wait a few more days. Lactos job is to produce lactic acid (put up pictures and curtains) and make the environment yeast friendly. (acidic). There are ways to feed a starter that encourages a LOT of lactos-hence the name "sourdough". Sometimes bad bacteria try to join the crew (usually from your hands-so wash your hands!) and they can make it look active and bubbly but usually they smell like bad cheese or gym socks. Sorry, but just throw the whole thing away and start over.

So now you have a nice party of yeast and lactos going on. After every feed they are rising to double. Now they are ready to build your house/loaf. After the feast (feeding) wait til they had time to eat (an hour or a noticeable rise) and then put them to sleep in the refrigerator until it is time to wake up and work. I wake mine up to make a preferment (very active population of workers) and then bake. Some people say they take a cold dollop and use it. I have never been able to have a nice loaf without waking them up in some fashion-preferment, biga,poolish, etc.

I hope that helps. Think about the task in concepts and it helps in knowing what to do.