Click on the "Register" link to the left, check the User Agreement and fill in the required information.
Make up a user name and fill in the "Anti-Bot" code.

Use your new usename and password to login. Be sure to check your email - you must respond to the verification that the HarborClassifieds automated system sends you.

You can change your password by Logging in, then going to "Membership" and click on "Change Your Password".
Remember, you have to be Logged in before you can see the "Change your Password" option.