Sure, just go to Setup | Customize | Contact | Fields and add custom fields for those items you'd like to store. Spouse's DOB would be a Date type field.
For section, go to Setup | Customize | Contacts | Page Layouts and click edit for the layout that you are using for your Contact record.
Drag and Drop the Section available in the palette below/above any other section and set the section properties such as Name, Display (Edit page, Detail page or both), Layout (single column/double column) and Tab Order.
Organize the fields with in the section and click Save/QuickSave to Save the layout and you are done.
Sure, just go to Setup | Customize | Contact | Fields and add custom fields for those items you'd like to store. Spouse's DOB would be a Date type field.
Do you want a new custom field or a section ???
For field, follow the approach given by Werewolf.
For section, go to Setup | Customize | Contacts | Page Layouts and click edit for the layout that you are using for your Contact record.
Drag and Drop the Section available in the palette below/above any other section and set the section properties such as Name, Display (Edit page, Detail page or both), Layout (single column/double column) and Tab Order.
Organize the fields with in the section and click Save/QuickSave to Save the layout and you are done.