Every Tuesday night (with some exceptions) there is a group that administers tests at the Cliff Cave Branch of the St. Louis County Library.
Sponsor: CLIFF CAVE VE TEAM
Time: 7:00 PM (Walk-ins allowed)
Contact: HARRY S NORDMAN
Location: ST LOUIS COUNTY LIBRARY/CLIFF CAVE BRANCH
5430 TELEGRAPH RD
DOORS OPEN AT 6:00 PM
CALL AHEAD WHEN POSSIBLE!
OAKVILLE/SAINT LOUIS, MO 63129
You'll need $14 for the VE testing fee and will need to fill out the paperwork. If you pass the test your callsign will appear in the FCC's database in about 3 or 4 days with the paper copy appearing in your mailbox about a week later.
If haven't taken any of the online practice tests I would encourage you to do so. qrz.com, eham.com, aa9pw.com, and hamtestonline.com are great places to do that.