Select Tools > Forms > Create New Form
You can have several different types of form elements in a pdf document.
Manage Form Data
With this option you can import or export data and you can also merge data into an excel document.
Track forms allows you to track changes made to a form and other various aspects of the form.
Form Field Recognition
Form field recognition allows you to take a pdf document and have acrobat look for places that could be used as forms. Note: in Acrobat 9 this actually works quite well and should be attempted before creating the form from scratch.