How can I use jquery to validate my form to check for duplicates in my mysql database?
You can send an ajax request, with or without jquery, from your form to a server side script that then queries the database to see if there are any duplicates.
After I have sent an ajax request and a duplicate is detected how do I output that in realtime?
Youll need a server side script (like PHP, ASP etc) to query the database to check for duplicates and then send the result back to the user's browser. Which server side scripting language will you be using?
There is a tonne of information on how ajax works on the internet.