There is a custom forms function within JobRoller which will allow you to have additional fields in job listing forms. You can see the custom form builder on the
JobRoller admin demo site. Changes outside of this would involve some customization on your part, however the theme is not encrypted, so you are free to modify it as you wish. There is no specific built in newsletter functionality, but you could potentially add this through use of a plugin and signup to a third party mail management provider.
The demo site is logged in as an employer which is why you can't see the job seeker functionality. When you are logged in as a job seeker, a dashboard button is there in place of the "Submit a job" button, and it's within there that they can add their resume information. Here are links to a couple of screenshots to give you an idea:
http://i.imgur.com/MyOlJmT.jpg
http://imgur.com/KLadfF8
Thanks.