How To Succeed in College/Success Inside the Classroom
In a Nutshell
Success in the classroom has a lot to do with your personal attitude and self-control.
Condition yourself to attend class, prepare, observe, listen, take notes, ask questions and discuss.
Make sure you are well rested. Try to have your A game on, but still have fun inside and outside the classroom.
The bulk of college courses are still taught through the medium of a classroom.
The effectiveness of classroom teaching can vary highly, and is highly dependent on your attitude, and somewhat on the tutor.
You have to quickly figure out two things:
1. Am I required to be in class?
Attendance policies may vary. Some instructors do not keep attendance records, and some instructors will count your attendance as part of your overall grade. It is always a good idea to attend class regularly.
2. Is attending class efficient?
Always attend class. This is where you will learn what information is most important for exams, and it also serves as an opportunity to ask questions when you need to. Your instructor has to be in class every day, so it is respectful to honor their time. When you can show your instructors that you are serious about the class by showing up on time every day, they are more likely to work with you when you have an issue.
When Attending Class
Make sure you can see visual material. Make sure you can hear spoken presentations. (It's worthwhile to go see an eye doctor once a year and have your ears tested AT LEAST once when you enter college)
Arrive early and find a spot where you can see and hear everything. The front of the class typically increases your odds of successfully hearing and seeing all relevant material.
Carry a notebook and pen and take notes. Make sure you know how to take notes: 
Maintain basic personal hygiene (bath, comb your hair, wash your clothes, brush your teeth) to make life bearable to those that attend class with you.
Your Classroom Tutor/Teacher
Your professor/teacher (or other tutor) is a key factor in your success.
This is the person that you have to convince that you have sufficient command over a subject to get a successful grading. He or she is also a human with strengths, weaknesses, likes, fears, hangups and quirks. Try to understand what those are and work around them. Listen carefully for clues about themselves when they speak. Talk to older students. Scan a few publications by that tutor, or look at web pages where the tutor is expressing him/herself. Take great care to always be courteous, respectful, and polite when talking to them, in spite of any quirks they might have.
It's important to realize that even in a large class, a professor can typically see exactly what everyone is doing. Most people feel that in a class of 20+ people they kind of "vanish". This is simply NOT true. The tutor can see exactly what you are doing, and especially so if you are doing something that differentiates you, such as talking to your neighbor, sleeping, doodling, playing games on your cell phone, and so forth. Activities such as these might earn you a mental note as a "non-attention-paying" member of the class and reduce your grade. When you are in class, mentally discipline yourself to pay attention, make eye contact, take notes and participate in class discussions.
If your tutor is good at explaining complex topics, you are fortunate and in for a treat. You will learn new things from an old salt that knows how to enlighten you. Unfortunately, this can be rare. That means you may have to ask questions to seek greater understanding. Not all teachers welcome questions, because it takes time to answer them well. If that's the case, go see the tutor in his/her office or after class and ask him/her to explain the issue, or ask via e-mail or via phone. If there is something you don't get, and your tutor can't explain it well, try other students (or teacher's assistants) or even other lecturers teaching the same subject, students that have successfully learned the material previously, or the Internet.
Your teacher wields a lot of power. Your success is literally in his/or her hands. Some students have a problem with that, mostly because they have a general problem with authority. Discipline yourself to view your tutor not as "the enemy" or an obstacle to your success, but a key partner on the road to success.
The college classroom will have an incredibly strong impact on your future.
Your mental attitudes before, during and after class will be a key contributor to your eventual success.