You're going off in a truly wierd direction.

99% of the time you can use apt-get to install packages. It's really simple:

connect to the Internet

as root do:

apt-get update

then (I suggest you do)

apt-get install synaptic

(which is a GUI front end to apt-get)

Trying to install from source is generally a waste of time and doesn't allow you to use apt-get to upgate packages.

There's an apt-get howto at the top of this page.

If you really want to unrar a package (.rar is an archiving method used in DOS and Windows) then you need to install unrar. You may (depending on your sources.list) be able to do a simple

apt-get install unrar

(I couldn't) or else do a google for

unrar debian

which should find you an archive with Debian packages (.deb). One of these will work out of the crate with 3.3. (The latest one requires that you update a fair bit of stuff and it probably isn't worth the effort).

You can install it with kpackage simply by left clicking on the icon.

You can then extract any .rar archive by right clicking on the icon, and selecting Open with ...... Ark.

And you can do the same for .zip, .tar and tar.gz packages too.