Networking,Zip Files

To your first question:
The user name and password you use to log in, is the same as were you to log in, at that computer locally.
To give each other access you need to create accounts for yourselves on those computers, and to give permission to view each others files you need to
1) select the folder/file you want them to view.
2) Go to File->Get Info, and set the correct permissions. Remember to click "Apple to enclosed items...".
3) Make sure the other user has at least the permission to read any folder higher in the directory structure.

Or you could drag all the files you want to share into the "Public" folder in your home directory, then other people can log in as "Guest" and view those files.


For your second question:
Find the drag-and-drop application "Stuffit Expander", place it into your Dock, now when you want to un-zip, un-stuff... a file just drag it on top of "Stuffit Expander" in the Dock, and it will expand the file to the current location of the file.

Hope this has been of assistance to you.

 

As far as compression goes, there are two ways to do it:

The first method is to launch StuffIt, select the type of compression you want, and drag the files/folders you want compressed to the window that says "drag items here" (if you've turned it on in the preferences - it's on by default).

The second method is to turn on AAVR (Automatic Archive Via Rename) in StuffIt Deluxe's preferences (I don't know if I have the name 100% right). Once that's done, renaming a file (from stuff.txt to stuff.sitx, for example) causes StuffIt to automatically compress the file according to the extension you used (for the example, a StuffIt X archive of stuff.txt would be automatically created for you).

 

This is off-topic, but you may have better success getting help with better spelling, punctuation and spacing .

Speaking for myself only, I gave up reading the question because it was too hard to read.