It too recommend the man pages, or perhaps even a Unix book. But these are the baics:

To create the tar file:
tar cf <tar file name> <file1> <file2> <file3> etc
Example
tar cf my.tar test1.txt test2.txt test3.txt
or
tar cf my.tar test*
Wild cards can be used with tar if you didn't know.

To see what is in the tar file

tar tvf <tar file name>

To extract the tar file
tar xvf my.tar

These are the basics. You may need to use other options depending on what you want to accomplish. If you just want to tar up a directory on one system and extract it on another, you could do this:

tar cf my.tar <directory>
this command should be run from one directory above the directory you are putting in the tar. If you do an ls, you will see the directory listed.
ftp my.tar (in binary) to the other system and put it in the directory you would like it to be under when you extract it then run:
tar xf my.tar

Hope this helps a little.