1 -Linux, unlike msdos, does not show directories as directories, and files as files. How can you differentiate when doing a dir?

2 - I downloaded FreePascal, saved a couple documents with OpenOffice, and everything went in the directory username@computername:~$. I'd like to make a couple subdirectories, but I'm afraid the path might not let the files be found unless I change it.

3 - I have downloaded some PDF documents. I know Adobe Reader is in here someplace, but can't open the files to read.

Any help is appreciated.