Topic: eccommerce / subscription selling site: signup flow

Im making a site which will sell monthly subscriptions and obviously want to make the singup proess to be as simple as possible for the user whilst at the same time secure for the business. Ill be looking at using spreedy to handly payments.

Can anyone tell me best practice for this?
Im not sure but i think quite a few ecommerce sites dont bother with email activation - or am i wrong? They just send a welcome letter???

Oh and Ive seen lots of social networking site signup tutorials but was wondering if its done differently for ecommerce.

Re: eccommerce / subscription selling site: signup flow

so this is my thinking so far

a potential customer views my plan and wants to signup.
They fill in their email address, password and then do credit card info.
Once payment is made and waiting for confirmation I tell the user they will be emailed once its been received.
If the payment is successful i save the client as a user.
I send a confirmation email of their purhcase.
When they want to cancel, they login to their dashboard using their email address and password. If they forget their password they simply request it to be emailed.

Note i havnt verified their email address here.
So im wondering if the customer made a mistake when they typed their email address they will email me and tell me so. But how can I verify that its really them and not an imposter? I request card details but is that locktight?