what do you think are the most difficult aspects of working with sources and making sure you do not plagiarize
It isn't really difficult to make sure you don't plagiarize. Just cite your sources at all times, and make sure you know the proper style you're working with. [ For most academic purposes this will be MLA, but there are other styles -- psychologists will use APA style, journalists usually use AP style, etc.
As far as working with sources, the most difficult part is finding and/or choosing the
best sources. There is no shortage of material to draw from, but the vast majority of it will be irrelevant, redundant, or just not the best out there. No matter how much research you do on a topic, you can still do more. ]
There are no new answers.