Typically, if a course is three hours/credits, then you will spend three hours studying and doing homework for every hour spent in the classrom.
A typical class is one hour long a day; these classes are often Monday, Wednesday, and Friday.
Another book you may be interested in reading: http://www.bartleby.com/185/
Money Issues:
Many undegraduates students go to a community college to save money. University courses cost more money to attend than a college; thus, people take similar courses at a college before transferring to a university.
Mathematic courses transfers to many public universities and colleges. I suggest you go to a community college first and take mathematics courses to the highest level of calculus offered. Four years of one language in high school is often required for entering a university; therefore, I suggest you take French.
Some people highly suggest mathematics, physics, and other science courses. I suggest someone who is taking residency in the Americas to take up mathematics and a modern language. If the courses do not transfer, you will be able to test out of the courses.
Calculus is calculus; French is French.
The arts and humanities are disputed.
It is easier to test out of mathematics than an art history course.
Another note:
Since you want to become a scientist, a university is well worth your time and effort.
The truth is, people need to have a degree to be trusted in society.
College and universities are all about status.