How do I add sub-users with their own log in info? So that they can only see their forms.

The sub-users actually have their own login credentials. In your Account Users page, you can edit the permissions if your sub-user can edit the form and view the submissions.

Please refer to this guide for more information about sub-users, here's the link: https://www.jotform.com/help/232-How-to-Share-Forms-with-a-Sub-account-User.

Hope that helps. If you are referring to a different issue, please let us know. Thank you.

What if I don't want them to view any forms execpt the ones they set up?

In the Account Users page, you can edit the permissions of your sub-users. Just checked the actions on the form you want to give access to. Here's an example:

Don't forget to click the "Update" button once you're done.

If you need further clarifications, let us know. Thank you.

Can the sub account user set up users to see their forms?

If your sub-users has a Free account, then they can have 1 sub-user. However, the forms in the main account that is shared in the 1st sub-user (your sub-user) cannot be shared on the 2nd sub-user (sub-user of your sub-user). 

Let us know if you have any questions. Thank you.

So they have to share the forms by adding in the e-mails when creating the form, correct? 

Are you referring about the email notifications? Yes, you can send email notifications to multiple recipients. Here's a guide: https://www.jotform.com/help/39-Send-Notifications-to-Multiple-Recipients.

Hope that helps. Thank you.