The hard part is the log-in and make changes to their information. There is currently no built-in way to give people access to just their own entry. There are some people working on front-end editing, or re-loading saved content back to a form to be able to edit it, but they are very technical and complex to implement.
Search through the forum for: front end editing and you'll see the number of people looking for similar things.
A third party add-on that recently came out might be able to help you with this. Check it out and contact the author to see if it could be easily adapted for what you want:
Posted 2 years ago on Monday April 30, 2012 | Permalink