Making a Starter

So I'm starting a new batch of beer this week. I'm still new to brewing and want to make a starter for this batch (my first starter). I bought the recommended amount of malt extract and everything for this recipe (red ale). My question is. For the starter, should I be using malt extract that would normally be going into boil for the starter? I.E. the recipe calls for 5lbs of malt extract, should I take the 1 cup out of the 5lbs malt extract for my starter? Or should I use 1 cup from an external source and then add the full 5lbs during my main boil?

You could probably get a way with using some of the DME from your recipe, but it will change your recipe slightly.

Typically, you would pick up a few pounds of DME to keep on hand for starters. Yeast starters are for bulking up the yeast. period. Nothing to do with the recipe. So - if you can get some from an "external source" that would be better.

You can use some from your batch. If you do, just pitch the entire starter instead of decanting off so you don't screw up the fermentable amount. It really wouldn't do much to the final gravity if you steal a cup for a starter when it comes down to it. But, like hang said, try to get some from an external source if you don't pitch the entire volume of the starter.