What are Folders?
There is a lot you can do with folders within RefWorks; they work similarly to file folders on your computer. You can create folders to separate your citations into groups, you can name them whatever you want to, and you can even share them with other folks with RefWorks accounts so that you can all add in documents, see each-other's citations/documents, etc.
Creating Folders
You will notice on the left side of the screen a list of options - including the 'My Folders' link.
Clicking on the 'My Folders' link shows you specific folder-focused options, including the option to Add a new one.
Clicking on that option brings up a basic box and asks you to name your new folder:
This is where you can pick whatever name makes the most sense to you. Naming the folder after your paper topic or after your class might be one way to go. RefWorks even gives you the option to Rename the folder later if you need to. You can alsocreate Subfolders within your folder.
Sharing Folders
Sharing folders is super easy. All you need to do is navigate to the left-side list of options and pick My Folders. From there, zoom in on the folder you want to share, and click on the blue triple-dot link 
to the right of your folder name:
The Share folder option is what you want to choose. Once you have clicked on Share folder, a box will pop up that looks like this:
You'll need an exact email address to invite them. Also, you'll see from the drop-down list below that there are three sharing options you get to choose from. Can Read is where someone can just see the citations that you have listed. Can annotate means that whoever you share the folder with can make annotations to the contents of the folder. Can modify means that whoever you share the folder with can add in things as they see fit. Choosing this option gives the person you are sharing with the most editing power.
Once you have shared your folder with whomever you wish to, hit the Share Folder option and you'll notice that little silhouettes of people now show up to the left of your folder name. This indicates that your folder is now a shared folder.
You can go in at any time and make changes to the sharing settings of your folder as you see fit.