Should I expect to pay around $30? Also, should I make an appointment beforehand or should I wait until I land and then just call them then?
They do flat rates. It's $29 to Schaumburg unless you're going west of Roselle, in which case it's $33 (plus tip in both cases). Just call when you land unless you're claiming bags, in which case, wait until the bags are coming out. They have cabs in the staging area, but the cabs are *not* allowed to wait (that's why you should wait if you checked bags). They pickup in the 2nd set of lanes, I know it's door G in terminal 1, they'll tell you what door for 2 or 3. It takes 5-10 minutes from when you call.
When you call, you will be given the number of the cab. Each of them has a 3 digit number painted on the exterior (front, side and back).
Make sure you wait for that specific cab. The assigned cab has to wait at the pickup area for a minimum time before they can leave (something like 1 hour).
There are a couple of rogue American Taxi drivers who try to short-cut the wait in the staging area and will try to say they are your driver. It hasn't been a problem for a while but it happened to me a couple of times about a year ago.