I'm to face the facts that you are here for partyi...-Academics! Right, right, academics. hehe, just kidding. You remembered that, right? ;)
Here classes are referred to as Modules. You can find the Undergraduate Module Catalogue HERE!!!
You want to make sure you either tick the box that says "Electives" or only search in the department under your home university. Chances being what they are, you probably won't get into your modules. Sorry, to burst your bubble. However: if you figure out all of your modules BEFORE you come to Leeds your like will be easier. WAY WAY easier.
Modules are registering are currently the bane of my existence. I know what you're thinking: "But I've survived WebAdvisor, the most particular registering software on the planet. I can handle anything!!" Well, the only thing worst that a crazy particular software a software that is not particular, at all.
The system that Leeds uses is through the Portal (equivalent to the Arch) and this thing will let you sign up for everything. This includes modules that occur at the same time as other classes and modules that last the whole year when you'll only be at Leeds for a Semester. Awesome.
To help you avoid that here are a few tips, in addition to GET IT DONE BEFORE SEPTEMBER!
1. Have a list of classes you want to take
Go to the course catalogue, look at the classes, briefly skim & then write them down as well as how many credits they are worth.
2. Exams
Go back to each page and determine whether or not the module has an exam at the end of the semester. If it does it will say at the bottom of the page under "Course Assessment." If you are avoiding exams so you don't have to take them when you've already started your 2nd semester back at Juniata, cross the ones that have exams off the list. This doesn't have to be a deal-break, but if it's a language course and/or it has an oral exam- cross it off now.
2. After you have a list go back to each module page and click "TimeTable"
Look at the timetable link and write the times down on the list as well.
3. List them in priority
Go back over the list and give each one a number of what you'd like to take the most to what you'd wouldn't mind taking.
4. Don't over email.
Start by emailing the department chairs (found here under "Academic Support"). Only email about 3 departments at a time to avoid enrolling in WAY too many classes.
If you follow these steps it should at least help you a bit, and keep you from being frazzled and entering classes a week late. Oh well as always Study Abroad's mantra is "Live & Learn"