How to take in income and expense information?

You can gather income & expense information from clients by turning on the "income & expense" section on a given questionnaire:

(this section is hidden by default for all questionnaire types except the "representative - on behalf of a living person needing assistance" type)

This section lets your client build up an overview of their income and expense:

Editing the categories for income and expense can be done from the "financial" section of the Questionnaire Customization screen:

The customization works the same way as for the asset categories: