Hello HoustonGirl,
I think you might benefit from our free InfoPath training labs. I'll paste the links below:
http://www.infopathdev.com/blogs/jennifer/archive/2010/06/25/free-training-learn-infopath-2010-and-sharepoint-2010-by-building-an-event-form.aspx
http://www.infopathdev.com/blogs/jennifer/archive/2010/07/01/free-training-design-your-infopath-form-template-lab-1.aspx
http://www.infopathdev.com/blogs/jennifer/archive/2010/07/08/free-training-lab-2-make-your-infopath-form-template-look-and-work-better.aspx
http://www.infopathdev.com/blogs/jennifer/archive/2010/07/14/free-training-lab-3-making-it-smarter.aspx
http://www.infopathdev.com/blogs/jennifer/archive/2010/07/23/free-training-lab-4-track-responses-from-your-event-form.aspx
But, to answer your question, yes, users need to have InfoPath installed on their machines, unless you have IPFS on the server, make your forms browser-compatible, and can direct users to the SharePoint form library so they can fill out forms in the browser.
Good luck!