Please use the guides provided below in order to learn how to register for courses, find information on errors you may receive while registering, and the websites you will use to look-up and add/drop courses.
Best place to look-up courses as you may search using various criteria, find course restrictions (limitations to specific majors), credit limitations (very important so you do not repeat credit), registration information, and much more.
Register for classes using "Enhanced" registration. Find your detailed or week-at-a-glance class schedule. View unofficial or order official University transcripts. Find financial and other student information.
http://registrar.illinois.edu/registration-procedures
How to register using Enhanced Registration, Registration Eligibility, Time Tickets, Holds, Enrollment Requirements & Prerequisites, and other useful information.