Want to allow users to post 'lost pet' notices

Hi

I’ve just downloaded WordPress 3 and Ive read it now has the ability to easily create custom post types. What I would like to do is allow users to signup and post ‘lost pet’ notices from the front end, and also allow admins to do the same on behalf of users but im not sure where to start 🙁

Does anyone have some good tutorials or resources I can refer to?