It's pretty easy to use the rm command to delete data. It's also pretty easy to delete the wrong data if you're not careful.

A simple way to avoid accidentally deleting everything with a rm -rf is to create a file named just -i in directories you definitely don't want to nuke. The -i will ask for your confirmation before deleting the files in question. Are you sure? Really?

Create the file with a simple touch -i wherever you want it. Your home directory is a good place to start. Don't want to burn down your home, eh?

There are many helpful online tips in the same vein. Check the following article for a neat shell expansion trick: safety when using the rm command

Also, be sure not to delete the wrong file and get into a $38 Billion mistake like these people did: ouch