At your service!
You're actually in luck if you're coming from St. Louis on Amtrak. Instead of going all the way to downtown Chicago and then backtracking, you can get off at Joliet. At Joliet's Union Station, you switch to another train, Metra's Rock Island Line. That will take you right to the venue in 15 minutes.
Here is the information you'll need:
Amtrak Schedule (
http://www.amtrak.com/timetable/oct07/W21.pdf) - assuming you come in Friday (or Thursday to see Paganfest), you'll probably want to take the #302, leaving St. Louis at 6:35am and arriving at Joliet at 11:14am
Metra Schedule (
http://metrarail.com/Sched/ri/ri.shtml) - it basically has trains leaving every hour on weekday mornings/afternoons. If the Amtrak is on time (ha!) you can catch the 11:24am Metra and arrive at Mokena (Hickory Creek Station, NOT Front St. Station) at 11:43am.
Going home on Sunday will be a little more difficult, because Metra doesn't run as frequently. If you want to catch the $30 #303 Amtrak that leaves at 10:15am, you'll need to get the first Metra of the morning, at 9:31am. If you're willing to pay $64 for one of the Texas Eagle Amtrak trains, or wait until the #305 leaves at 6:05pm, then you'll have an easier time of it.
For reference, here is my original airport-to-venue post:
http://www.ultimatemetal.com/forum/...71-using-public-transportation-get-venue.html
Neil