Hardly naive. Creating symlinks isn’t exactly ordinary Macintosh usage. It is a function of the underlying UNIX system which, at first glance is kind of confusing because it seems to be just like aliases (and indeed when you are using a UNIX system that is what they are used for)—and in a way Finder treats them like aliases on the surface, but they are a bit different (for one thing they do not track the original file if you move it).
There might be an easier way of doing this with a bunch of GUI razzle-dazzle, but the way I always make them is to open up Terminal.app and type:
ln -s ~/Documents/school ~/Dropbox
ln is the command to make a link. The “-s” tells the system to make it a symbolic link (symlink for short. The other mode is a “hard link” which is entirely different and has restrictions that would make it not useful for Dropbox), then the first part of the command is the source file or folder “school” in this case. The “~” at the front is just a shorthand way of saying “my user folder, wherever that may be”. The second part of the command is where to put the link. In this case, I reference the default DropBox location. This will create what appears to be an alias called ‘school’ in the Dropbox folder. If you wanted to call it something else, you could have specified the new name after the Dropbox part, like: “~/Dropbox/schoolwork”
It looks like Dropbox is doing something “magic” with the symlink. Instead of just storing the link itself which is an empty file with a pointer to the original, it is storing the full original file. What I haven’t tested is going onto a second machine and accessing the file from there. Does it automatically create the file in the appropriate location? I’m not sure. I just played around with it enough to note that it was storing data in the web interface.