I found this at Mac OS X Hints and thought it was a fine example of shell scripting. This particular example is used to make backups of certain game files, but could easily be seasoned to your tastes. BTW, backup often, and backup twice
OS version: OS X
set right_now to do shell script "date | awk '{print $1,$2,$3,$6,$4}'"
do shell script ¬
"cd ~/Documents/\"Agent Backups\"/ ; tar cvf \"" & ¬
right_now & ".tar\" *.usr ; gzip \"" & right_now & ".tar\""
-- the next three lines are one long line, but you'll have
-- to manually combine the last two segments, as you can't
-- put an AppleScript line break in a shell command!
do shell script ¬
"cp \"/Applications/Games/Uplink 1.0.0/Users/\"*.usr
~/Documents/\"Agent Backups\"/"
launch application "TextEdit"