SSL in a wordpress website

Suppose I'm creating a Wordpress website with user login an开发者_JAVA百科d a small e-commerce.

When user logins in, she uses http://www.mysite.com/login/. When se buys something, she uses http://www.mysite.com/mycart/ where credit card info is entered.

How do I use SSL in this setup? I mean, I should redirect http://www.mysite.com/login/ to https://www.mysite.com/login/, and return to http, then when in http://www.mysite.com/mycart/ to https://www.mysite.com/mycart/? How do I do all these redirects?

(I'm planning to use a SSL from a shared hosting environment)

Start with the official documentation - and then integrate your shopping cart.