Fill out two forms: the course approval form (for the school) and the registration form (for the college)
Usually, the college needs you to make a student ID so follow the directions on your college's website to create an account.
You must also get an approval form when taking classes during the summer.
Make sure to consider how many classes you can take at a time; some colleges require you to stay below a certain amount of credits.
Set up a virtual appointment with Mr. Lam (VP) to get your courses approved.
This is where you tell him if you want your college courses to count for credit for high school classes or not. SCHS students are allowed one class that can count for credit a year so choose wisely.
Turn in you course approval form(s). You can find the registration form online and fill it out digitally. Send the form to Mr. Lam and he will be able to sign it much faster and he'll be able to send the form directly to the college.
Register for your classes on your college account.
Now you wait for the class to start or for a spot to get off the waitlist.
The UC's and a few colleges like Johns Hopkins and Columbia hold online courses; the process to enroll is the same.
For Coursera and edX classes, you must check to see if the classes you want are eligible for school credit.