1st time yeast starter question

I'm getting ready to attempt to make a starter for the first time. I've got about 6 batches under my belt using smack packs. (always seemed to work fine). But every one here swears by doing it. My question is how long can the starter sit before i pitch. I'm away 4 days a week, I like to brew on my first day home,so the starter would be 4-5 days old before I used it.

thanks

it will be fine to sit that long. Just make sure it is as large as you want it to be since you wont have time to step it if you make it then will be getting back and using it in 5 days. Just sanitize real well and taste it before you pitch to make sure that it still is ok to add to your wort. I have let starters sit for 7 days and they were fine.

Each step up should be no more than 10 times the volume of the last step up.
This is a good resource. You can make your biggest step up in a gallon glass container with sanitized aluminum foil over the top. I have made even bigger ones in a carboy too. Extra wort from a previous brew makes a really good starter because grain has a lot of good yeast nutriants in it. You can make extra wort each batch and put it immediatly in the refrigerator. If you are going to keep it a while it must be pressure canned.