a password is required for me to delete files. how do I turn this off?

You don't. Where are the files? Are they in your home folder or elsewhere? The former you shoudln't have to enter a password, and the latter you always will.

Are you logged in as an administrator, or is this a file you should be deleting? Try repairing your permissions, take a look at this link, http://support.apple.com/kb/HT1452