This is real simple to get to Kevin.
Don't take I-88.It's $10 in tolls in either direction,and slower cause it's under construction and down to 1 lane in many random areas,as well as it's more confusing for a newbie to get to Peotone.
...plus why pay $10 to slow down or sit still.
I took it to Iowa Gas in July and came home on I-80 faster & richer.
If I was you,I would take I-39/51 directly south to I-80.It's free & it's easy.
Then turn east and take I-80 all the way to I-57.(I'll be at that junction @ 7AM).
Then take I-57 south all the way to exit 327,which is Peotone.
Head east 1 mile after that exit and when you come up to the R/R track crossing,(DON'T CROSS THEM),turn north and it's right there on your lefthand side.
Just pull into the p/lot at the Will County Fairgrounds & walk into the brick bldg...i.e. swapmeet.
Call me if you have any trouble.