Subscription forms/memberships for a wordpress site

Hi, i am having trouble setting up a free membership on my site. Heres what i would like to do…

visitors will come and have access to most of the pages on my site however there will be a few select pages that i want to restrict from people unless they become a member by filling out a subscription form. i want to put the “subscribe button” on my home page, once the visitor hits the subscribe button they will be redirected to the subscription page. they will fill out their name email etc and hit submit. once they have subscribed, they will have access to all of the content and pages on the site. every time they re visit the site they will only have to enter in the user name and password.

How should i go about setting this up?