to install Jetpack I also have to sign up with wordpress.com, is that correct?
That's correct. The Jetpack plugin requires you to connect to a WordPress.com account to be fully activated. You can create a WordPress.com account here:
If you had previously created an account, but forgot the password, you can request a new password by entering your email address here:
I'm just trying to figure the best plugin to use for my site. I'm debating whether to use Feedburner or jetpack. Thoughts?
Jetpack and Feedburner are different, since Jetpack includes many modules, and doesn't only deal with subscriptions.
You can find out more about the Jetpack Subscriptions module here:
That should help you understand the differences between Jetpack Subscriptions and Feedburner.
Also will jetpack be good for a plugin to have as a way for visitors who subscribe to my newsletter and get a autoresponse and a sample of an ebook.
Jetpack allows you to customize the contents of the confirmation email that is sent to your subscribers when they originally subscribe to your site. You could include a link to a sample of an ebook in that email.
Once they have confirmed their subscription, your readers will receive a notification email every time you publish a new post on your site.
You won't, however, be able to email them without publishing an entry on your site. If you want to do so, you will have to use a different newsletter management plugin.
I hope this helps.