Students on F1 visa are eligible to work on on-campus jobs at the university which issued their I-20 (in simple terms, in their own university). On-campus jobs comprise of various positions like teaching assistant, research assistant, library support and other helper jobs in dining halls, university bookstore, gymnasium/athletics center, positions in various academic offices, IT positions that involve maintenance of university computing infrastructure and websites etc. Working on off-campus jobs is prohibited for students on F1 visa.
Students can work only up to 20 hours per week (part-time) while the school is in session. When the school is not in session (i.e. Winter Break, Spring Break, and Summer Break), students can work full-time. Full time is usually 40 hours per week, but might be less in some universities.
Universities have online portals where campus jobs are advertised. Many departments post job offerings on department notice boards. Asking around for jobs with professors and fellow students also helps. For example, here is the student job listing page of OSU and the on-campus employment website of NYU.
It totally depends on the kind of job and university. Typically
work that doesn't require any domain knowledge pays less than the
work that require specific skills (eg. web development, networking
know-how). The payouts usually range from $8-$15 per hour. Some
RA positions can pay as much as $30 or more per hour - it depends
on the project and how well the department/project is funded.
On average, it is reasonable to expect $10 per hour.
Let's suppose one gets $10 per hour. With an effort of 20 hours
a week, the payout is $200 per week, which is equal to $800 per
month. With $800 a month, one can definitely pay for most (if not
all) living expenses.
Let's do a quick calculation of the living expenses:
On average, you can assume it to be somewhere around $400 - $900
So coming back to the question, can one rely on his/her campus job to pay for the living expenses. While numbers show that you can depend on campus jobs to pay for most of your expenses, however, you should not rely on it. Do not take campus job into account when you are planning your finances. There is no guarantee that you'll get one (unless you've already been offered a job in advance) and even if you get one, you cannot be sure that you'll be able to keep it for the entire term or put in 20 hours a week.
Plan your finances without picturing a campus job. If you get one, its a plus and it'll be a big help, but don't depend on it. Also during the visa interview, when the consular officer wants to see finance statements enough to cover your study expenses, he'll want to see something that is in hand (liquid assets, property etc.) rather than something that is just a promise. Campus job might help you in corner cases, but if you are falling well below the funds required, campus job will not plug that gap.
No. Campus jobs will not be sufficient to cover your tuition fee. Even if you consider doing intermediate stints of full-time jobs between semesters, in maximum cases the money won't be enough to cover your tuition fee in its entirety
The best source of infomation about on-campus jobs is the Office
of International Education (the name of the department is
different in different universities).
You can refer to the official USCIS website for more
information on On-Campus job rules and regulations:
http://www.ice.gov/sevis/employment