Hi ZenLikeMe and welcome to our forum,
There are some scenarios where opening a new form is the right thing to do, but for sub-sections of your form, I would add sections that hide/show based on a condition, or like Franck suggests, switch to a different view. You can also look at the taskpane.
Patrick Halstead [InfoPath MVP]
InfoPathDev
Patrick Halstead
Project Manager at Qdabra