This course is based on Algorithms (4th Edition). The textbook and lecture slides were developed by Robert Sedgewick and Kevin Wayne for their undergraduate course at Princeton University. They also have an excellent Coursera course that covers much of the same materials as this class. You are welcome to watch their Coursera videos in addition to attending lectures to reinforce the course materials.
Penn offers free tutoring for students for several intro classes including CIS 121. You can seek additional course help here. In the past the tutoring center has been oversubscribed for 121, so we encourage you to sign up at the start of the semester if you think that you’ll need help.