(1) PLAN
I think that our generation is notoriously averse to logistics. Spontaneity is a value that we respect, and contingency is thought to lead to unplanned excitement and opportunity. It can also lead to a whole mess of problems, especially if you are doing something relatively sensitive, like giving a presentation on your own work in front of a room full of strangers. So be proactive in planning the functional necessities of your conference trip; if you are not worried about how you are getting there and where you are staying, you will have a lot more time to worry about your paper!
When are you presenting and need to be at the conference? Do you want to stay longer (and have the funds to do so)? These are some early questions to ask as you make the next steps.
Once you know that you have been accepted and when you need to be at the conference, the first step is to find other people in your program who are also going. Are these people wanting to carpool or split a hotel room? (If you are in the Midwest, CSAS will generally be within driving distance, even if it is a long drive, so there is no need to deal with expensive airplane tickets outside of mere comfort.) Also keep an eye on e-mails sent and forwarded by conference organizers, as sometimes there are people from other schools who are looking for people to share hotel rooms with, travel with, etc. This is going to keep your personal costs down if they are not covered by your university.
RESERVE YOUR HOTEL ROOMS EARLY. Conferences will usually allow attendees to make reservations at a fixed and reduced rate, but this discount will have a deadline and may be first come, first serve. With most major hotels, reservations will only take a few minutes and will not require payment until you actually show up for your reservation; doing this early will ensure you are not paying twice as much (if not more) if you try to reserve a room a week before.
(2) PLAN SOME MORE, COMMUNICATE.
So you have taken care of the basics. But unfortunately, plans change, and some people might be hesitant to mention that their plans have changed. It would be wise to keep in touch with people you are driving/rooming with to make sure they are still good with the itinerary. If not, try to find alternatives or compromises. If your plans change, makes sure to let others know quickly.
Also, inform your professors that you will be gone from class. You know months ahead of time when you will be gone, so they should have advance notice as well.
It is also time to work on the scholarly side of the conference. Get that presentation ready, make sure your PowerPoint looks neat and that your verbal presentation is trimmed down to 15-20 minutes. If you have flashcards or a paper that you want to read from (this is common at conferences, even major professional ones, so do not feel like you need to be completely offbook), make sure all the pages are there and whatever notes you make are clear and legible. I like to keep a separate folder with all of these things, but you do you. These are also things that you can double-check at the last minute if necessary, but having them in line early is wise. (Conference hotels will generally have a business center for guests that can be used for printing, etc.)
You will have advance notice of the other presenters on your panel, your panel organizer, and your discussant; it might be a good idea just to e-mail these people in advance to introduce yourself. It is a very good idea (some might say imperative) to get a draft of your paper to your discussant early, at least a few weeks before the conference.
As you pack, think of those things that you will need that the hotel is not going to provide for free. Toothpaste? Deodorant? Maybe bring your own snacks, as it might be tricky to find food late at night. Bring a swimsuit if you intend to use the pool. Generally, try to think of those little things that you are going to miss once you have realized you did not pack them.