I'm looking for a way to do the following:

When I get an email address of a lead, I want to put him on a schedule that will email him once a week for 8 weeks using pre-defined email templates.  

I.e. Joe Smith signs up on my website on 1/1 - I want to email him on 1/1, then 1/8, then 1/15, etc without having to do each email manually

Then Jon Smith signs up on 1/3 - I want to email him on 1/3, 1/10, 1/17, etc

Is it possible to set up automated campaigns like this?  I see how I can mass email a bunch of leads at once, but I want each person to get a series of emails starting from when they sign up.

Thanks!