When you open the Index Viewer or Document Viewer for a document, you will see the Index Field Pane on the right-hand side (and the Table Field Pane below, if that has been configured). This is where indexing data is entered and stored.
You can type in your data and use your mouse pointer or keyboard TAB key to move from Field to Field. With v5 KeyFree Indexing, you can add data with a click of your mouse button. The process of indexing data can be fully automated as part of a Workflow process. Refer to v5 Edit Data and Documents for details on indexing documents.