To start out, here are a couple of great references.
http://www.howtobrew.com/section1/chapter6-5.htmlhttp://www.mrmalty.com/pitching.phpMy abbreviated version is to make up about a quart of wort with a gravity of 1.030-1.040. Any stronger than that will create osmotic pressures that can damage cell walls of the yeast. It will help to add a pinch of yeast nutrient to that. This wort will need to be brought to a boil and then cooled to pitching temperature. This is to give you a somewhat sterile culture for the yeast to grow in.
Next you need to aerate the wort. If you are doing this in a big jar, sanitize a lid and place it on the jar and shake the crap out of it. This will put the O2 back in the wort that the boiling drove out of it. Those of us that have some spare cash, do our starter in an Erlenmeyer flask and use a stir plate. You can also use a wire whisk or something similar to get a bunch of air mixed in. After pitching, give the container a good swirl every time you happen by. This will get some more air in there.
Next, pitch your yeast. You don't need to be real picky about your temperature since you are growing yeast, not fermenting beer at this point. Temperatures in the upper 70's into the 80's are just fine for yeast growth but make for lousy beer. When the starter is ready, you will need to lower the temperature of the starter to the recommended pitching temperature for the particular beer you will be making.
Some folks get concerned when they don't see any activity in their starter. Most of the fermentation will take place in the first 18 hours. Generally you will want to get your starter going the day before you brew. Quite often all the activity will take place while you are asleep. You just need to take a look at the starter to tell if anything happened. You should seen an increase in the amount of yeast that has settled to the bottom of the container. If you are using a stir plate, you will notice that the color of the cloudy wort has gotten lighter.
When it gets time to pitch the starter into your fermenter, you can generally dump the whole works into the wort. If the volume of the starter is a quart or less, it generally will not affect the taste of your beer. If over a quart, you will want to decant the yeast. Simply stick the container in the refrigerator first thing in the morning on brew day. After an hour or so, most of the yeast will have settled towards the bottom. Just pour off most of the liquid over it and then let the yeast warm back up to room temperature.
Hope this helps.
Wayne
