Originally posted by petey
Hi all, and apologies if this has been covered elsewhere. I'm new to p2p and have only been using a mac for six months so please forgive my ignorance (it's not wilful I promise!).
Hi and welcome. We are happy to forgive ignorance, especially since we ourselves are afflicted with it so often.

1. It took me a while to figure out that the destination folder for downloads was hidden. Can I change this folder to a location of my choice without screwing anything up?
Yes. In aMule preferences, Directories, Incoming Directory. Set it to anything you like. Be aware that the contents of the Incoming directory are automatically shared.
2. I was a little confused by the location of files I wish to share. By this I mean that the 'Shared Directories' option seemd to be suggesting that all folders on my computer were open to the outside world. Is this the case?
No, you've misunderstood. That control allows you to browse all the folders on your computer. If you want to select one to share, double-click it. It will turn bold to indicate it is being shared. The icons of all of the containing folders will change color to indicate that one of their children is being shared. When you share a folder, only its immediate contents will be shared. aMule will not automatically share the contents of folders inside that folder. If you wish to share a folder and all its subfolders (and their subfolders, ...), then control-click (AKA right-click) on its icon. This is just a shortcut for you drilling down and double-clicking each subfolder manually.
3. Can someone please explain to me the best way to set up and locate folders for downloads and for sharing. I am concerned that I have not put my shared folders in the correct place, as it appears nothing is uploading.
There is no "best" way. It depends on your individual needs and intentions. I suspect the answers to your questions above will give you the information you need to achieve what you want. If you still have questions, tell us what you're trying to achieve and why your current setup isn't satisfactory, and we can give more advice.
Good luck.