For those students who come in without aid of any kind, it is going to be a long search. You will have to keep contacting your Professors and lecturers and ask them about your chances of getting aid. RAs or TAs are not just restricted to the departments they are enrolled for. So basically a student will have to visit each department and give his resume there and hope that he is called for an interview. Usually the Departments advertise if they have any openings.
Jobs are fairly easy to come by.
There are different kinds of jobs on campus. A student is not just restricted to his department. He can work anywhere on campus as long as his paymaster is the University. A lot of students work in the Library, shelving books or manning information desks. Some of them work in the computer labs.