In general, classes in Taiwan were structured rather differently from what I imagined. Language classes (aside from General Chinese) are 3 hours once a week. Most exchange students take 15~20 NTU units (about 3~5 courses), whereas Taiwanese and Chinese exchange students take 20~25 units (5~8 courses).
I took 19 NTU units, a total of 3 Chinese courses, 1 UX, 1 art history class, and 1 independent study. I was afraid of being overwhelmed with work when I first started since this is already 6 courses, but I realized that the workload is a lot lighter per class when compared to UCLA. Depending on some classes though, you might get a lot more work. I say it's totally possible to take 20~25 units and still have a good chunk of time for traveling and having fun.
When choosing classes, I recommend checking out:
EAP List of Pre-Approved Courses - These courses will guarantee that you get the credits needed for your minor.
Courses for International Students - These courses are designed for international and exchange students, and are mainly taught in English.
General and Enhancing Chinese - Language courses created specifically for exchange students. I have heard that Enhancing Chinese is more useful than General. (Note that you MUST take General Chinese in order to take Enhancing)
Applied Chinese - You can learn Taiwanese and local culture through these courses.
Online Course Information - Schedule of classes for all students. Check here for courses that local students take, as well as for major-specific courses.
Courses Taught in English - It is possible that the teacher's English is not as great as you'd expect.