I want to implement user stories in a new project where can i find a good template or other ones used in agile development?
Alistair Cockburn has a use-case template. Dan North adopts it to user stories.
The best template I have found is:
As a <user> I want to <do something> so that <I can accomplish goal>.
See the Nine boxes technique to elaborate your user stories. It's not really a template per se, but it leads to filling the "as a user, I want ... so that ..." template, which is very efficient. Mike Cohn is explaining this better than I would.
It also allows to discover non-functional requirements (the ilities).
EDIT: the original link ( http://dnicolet1.tripod.com/agile/index.blog/1765142/nine-boxes/ ) is now cybersquatted. This answer is now pointing to one copy of the Nine Boxes page in Google cache and archive.org.
Remember that the meat of a User Story is in the conversation with the Customer, and in the automated acceptance test: http://www.xprogramming.com/xpmag/expCardConversationConfirmation.htm