I would just wait. Seriously wait until you finish one week of school. Your professor nay recommends or advise against certain supplements. Or he might be the type that trys to tell you you don't need any supplements and if you use them you will fail his exam. Follow along in class, go browse at the bookstore a time or two, and then buy. You'll probably get out for half the price you would if you just bought everything on the shelves.
I've gotten flamed in the past for suggesting that supplements are a waste of money, but I really think they are. Our school has supplements available to borrow for free from the Dean of Students Office, and I have heard other schools have them in the library. You might want to see if your school has something similar, because at least that way you can check out what is there before you buy. Also, some of our professors mentioned supplements that they particularly liked, so those would be a better investment IMO. I did like the flashcards, but I never bought any, I borrowed what I needed. We used them to drill in our study group toward the end of the semester, and they are not a bad review. The future interests set for property sticks out in my mind as being a very helpful set for a very confusing topic. I've used (borrowed) some E&Es to brush up on certain concepts before an exam, and I've worked through the questions in them as review before the final. They are not bad, but they are broad and not always tailored to what your professor has focused on in class. I can't comment on the Gilbert's, I never used them. The one supplement I did purchase this year, which I found very helpful, was Chemerinsky's Policies and Principles for Con Law. Our casebook was not helpful and neither was the prof, but I found the Chemerinsky book really clarified things for me.There is a lot of debate about the usefulness of supplements on this board and in law school classes. I like them as a review/refresher at the end of the semester but that's about as far as I go. And I am very cheap, so I hate the idea of spending money on things that may not help me. Additionally, I would not advise reading them instead of your casebook, though many people in my class have done so. Also you may find that some professors are clear enough that you don't need a supplement for their class (my contracts class was like this). I realize this is a muddled post, but I hope it is somewhat helpful. You will probably get loads of replies from people who successfully used supplements too.
Here is what I was thinking to get while I am in school for my 1L1. Emmanuel's 1st year flash cards (all 1L classes)2. Gilbert's First Year program for outlines (includes for all courses)3. Examples and Explanations for all 1st year coursesIs it necessary to get all these because it is going to be like 500-600 bucks right here, on top of whatever I need to buy for my actual classes at school?