The requirements for the CS major, CS minor, and certificate in applied CS (that can be earned by non-degree students) are listed in the undergraduate catalog.
Other Courses, Sequence of Courses For advice on which other courses to take and which order to take the courses in, see the undergraduate advising page.
Concentrations The CS major consists of 30 credit hours of required courses, 6 hours of electives, and completing a concentration in either "Computing Science" (17 hours) or "Information Science" (15 hours). Here are some thoughts on the two different CS concentrations. The Computer Science concentration has courses that have traditionally been a part of CS majors. These courses focus on the fundamental principles and analysis techniques at the heart of computation. The Information Science concentration has courses that in the past were often electives, and are focused on particular problem areas. In general, the Information Science courses are more likely to be directly applicable to entry-level jobs, while the Computer Science concentration courses are more likely to stretch your mind and develop problem-solving techniques that you would not be able to learn on your own.
Given all of that, the recommendation is to do as much of both concentrations as you can fit into your schedule. From the Computer Science concentration, take CS 420 and CS 458 if possible. From the Information Science concentration, take as many of the courses as you can fit into your schedule, and prioritize based on your interests. If you normally do well at math courses, take Math 131 and Math 132 early in your time at ISU (while your previous math courses are still fresher in your mind) to keep your options open.
One last thought... If you plan to aim at the most competetive CS jobs (e.g., tech and software companies), those companies are used to hiring people that have coursework from the Computer Science concentration. That is, if you are an A student in your CS courses and want to have the most options when applying for jobs, take the Computer Science concentration, and do as many of the courses from the Information Science concentration as possible. If, on the other hand, you likely want to stay local or work for a smaller company (possibly a company where you are one of the only people with a CS degree), these companies are less likely to care whether you have taken calculus, and more likely to want you to have some experience with whatever software package or problem domain they want you to work in.