It also really depends on which university you go to. The balance of coursework to exams will vary quite a lot, so this will affect what you actually do. "Unistats" will tell you these percentages for the course.
When handing in coursework, it's rarely given to the teaching assistant or lecturer for that class - You'll hand it in at an office or submit it online. You'll also score zero marks if it's a minute late, so get used to doing things well before time. The staff really aren't too bothered about seeing you because they're busy with their own stuff... Of course, they can usually make time to see you, but they deal with so many students and classes, so you usually have to find other ways of getting through the course than their help.
Self-study and collaboration is important for success... At college you may have 5-8 hours per class per week, but at uni you may only get 2-3 hours of contact time with a lecturer or tutor for that class. Thus, you'll have to team up with people to work through problems and generally find other ways to do your work.
There are usually past papers for exams, but I found they weren't as extensive as they were for A-levels. Because each university sets their own exam papers (there is no national exam-board, although the papers will have to meet certain standards, especially if the university is accredited) there isn't as much stuff to revise from. On one class where the year was split in two (half did it before Christmas, half after), the lecturer told us that the coursework for us would be harder and the exam would be easier because he was the one who was setting the questions.