I'd like to have an area in my form with a portal (I'm used to access, so I'm not sure if this is the right tool to use) for simply viewing records that have been linked to the initial record, say employees linked to the company, but not have any way to input the employees on that initial form. Then I'd like to have a button that allows me to pop-up a window to input a new employee into that company. Can a portal be just for viewing? I don't see a way to set that up. Also with the buttons I see an option for popping up a new window, but not for popping up a new window and going to a different layout? How do I accomplish this? Thanks!

Can a portal be just for viewing? I don't see a way to set that up.

Select all the fields in the portal and make them non-enterable (Inspector > Data > Behavior > Field entry).

Then I'd like to have a button that allows me to pop-up a window to input a new employee

You need that button to perform a script with several steps (New Window, Go to Layout, New Record ... ).