Utter Confusion: Documents/Images

I am in utter confusion about images on my Mac.
Some questions:

1. Images I get in the Mail App-where do they go, do they take up space and can I delete them?
2. If I drag images to my desktop, then to iPhoto for an album-they are in iPhoto, but still on the desktop-I want them off my desktop. If I put them in the trash, will they be deleted from iPhoto? Where do I move them so that they are still in iPhoto but not in my desktop.
3. When saving a document, the drag down is not like Windows-where I can navigate to anywhere in the computer-how do I make Mac like that? Right now, I cannot navigate to folders within Documents, How do I do that?

Thanks in an advance.

1. Document>Downloads, yes they take up room
2. Delete them from the desktop. iPhoto copies it to it's own folder.
3. The arrow on the upper right points to the drop down toggle. The one on the left points to the different view options. Down the left side you can navigate from any attached disk to whatever file you want.

1. Images that are downloaded from the mail app go to the downloads folder, which is a stack on your menu bar.
2. If you drop and drag from your desktop to iPhoto and don't want the pics on the desktop, simply drag and drop them on the pictures folder so you always have a copy.
3. If I am perceiving correctly, Its a view preference. In the menu bar at the top go to view> click on last. And at the bottom of the view tab turn on show toolbar.


I hope I helped and Please, I wanna hear your results.