Here's another question for you all. It's not related to the academic side of university, but I still think it's a really important question.
How did you find the transition from high school to university?
My advice will probably be more relevant for people who moved out of home and chose to live on campus, but that environment makes it pretty effortless to make friends and meet new people. The problem then is taking the effort to make friends with people who don't live with you
The biggest advice there would be to not stay holed up in your room, if you just want to chill just sit around in one of the common areas and talk to anyone who comes by. There'll likely be a lot of activities happening around the student residence and on campus too, so definitely get involved in some of them.
I'd skip all, if not the majority of the boring study skills sessions that come up during O-week, that's valuable time you could be using to eat free food or socialise. You don't need to learn how EBSCOHost or other journal search engines work in the first week, you can easily pick that up later in the semester. Those essay skills sessions will be pretty broad, and not immediately useful - you'll be told those kind of skills in first year classes anyway. And so on. Definitely go to something where they advertise the clubs and societies, and see if there's anything that interests you. Attending one of these, even if its irregularly, is a great way of meeting people or picking up new hobbies.
Perhaps more relevant to people moving out, but spend some time to explore the local area outside of the university too. Mark out where the cheap supermarkets and what else is within walking/quick travel distance. Learn to cook something basic... like pasta
http://lostoncampus.com.au/ <-- self-explanatory, this is probably the most convenient map. It helps in the first few weeks, a lot.
If you've rocked up to a lecture early, don't go inside and sit down. Unless it's a full lecture theatre, you'll probably find you'll end up sitting by yourself (or sitting next to people who are talking to their own friends). Instead, stand around outside and talk to people and then sit down next to them.
For the more academic things, your lecturers will have contact hours, it's good to go to them, even if its just to have a chat about the course. Most lecturers will be more than willing to help. Also go to the library, and look at the books relevant to the course. Books outside of the assigned textbook are pretty damn useful for different perspectives of explaining the same thing, or something your textbook missed out.