Profile as in a Social Network Site i am creating a social network site. I want when the users clicks join after entering his initial details such as name, email and password (the user does not need admin approval for account to be created) he or she is taken to a user registration page which looks like: 
http://imgur.com/fa31Xt1

i know how to add fields from admin/settings/people but should i use profile 2 module? if so how exactly...also once the user clicks save profile (as in link above) then he or she is taken to his profile page where he can view his profile
You can control how the user is redirected after login using the Rules module.  Create a rule using the event User logs in and action Redirect to page.  You can create as many redirect rules as you need to get the user to go to the appropriate destination.

For example, for my social networking site, I do the following:


redirect users who haven't completed their profiles to a page telling them they need to do that (condition: user doesn't have profile_completed role)
redirect users who have completed their profiles and have new messages (from private message module) to the message inbox (condition: custom PHP condition)
redirect all other users to the search screen


In my implementation, I actually implemented this as a rule set (component) instead of a bunch of individual rules so that I could easily achieve the third option ("redirect all other users").