U hv two options.
Type in the address bar http://profiles.yahoo.com/abcd where abcd is the user id. U will be able to find the person’s profile available with yahoo.
http://members.yahoo.com
Please click the above link. There u will find "Find People" There u will find a search box. Click the arrow of the box, out of drop down menu selcet yahoo ID, enter the yahoo id in the search box , click search now. Yahoo will display the info about that person whatever has been provided to yahoo.