Your find line:
Don't forget \! -name Users

Otherwise, yes It would not delete JoeUser, .localized, Shared, nor $USER.

You definitely want to exclude Users, as that would get deleted if it's time stamp is older than a day. Bad, since every home folder you wanted to keep would get deleted too.

You could remove the "exit 1" line from the script so that you still get notification that your admin user account/s will not be deleted. Your first if statement would then just for the notification, proceeding on to the find and delete operation. It should look like this:

Code:

# If home directory exists, delete 
find /Users \( \! -name Users -and \! -name JoeUser -and \! -name .localized -and \! -name Shared -and \! -name $USER \) -maxdepth 1 \! -mtime -1d -exec rm -R {} \;
dscl . -delete /Users/"$USER"
exit 0

---------- Post updated at 05:55 PM ---------- Previous update was at 05:32 PM ----------

As far as creating your own goes:
Advanced Bash-Scripting Guide

Verrrry handy.

Other than that, there's a "Learn Shell Scripting in 24 Hours" which even if it takes 24 days still isn't bad. Also web search, maybe even a quick and dirty Unix class at a local Community College?

It should be said that there is usually more than one way to accomplish the same task. Some might make use almost exclusively of awk, while others might never get much outside of python. Still others might scoff at not using ruby.

I've found that these Unix forums provide real examples of tasks one might need to perform, particularly Shell Programming and Scripting, Unix for Dummies... and Unix for Advanced. I have spent a few hours since finding these forums trying code out to see what it does. If the commands are not exclusive to a particular version of Unix, then it will be informative.
I find shell scripting (bash and/or sh) to be adequate, if admittedly sometimes clunky, for my needs. Learning something else is almost always limited to finding I cannot complete the task in the shell by itself. My most recent tenuous forays into the unknown have been simple awk line parsing with it's marvelous print function.
Pretty darned rare, but then I'm a simple kinda guy.