Administering security credentials (Office SharePoint Server)

Listed TechNet articles discuss password changes for different service accounts

MOSS

• Change passwords used for administration accounts
  
• Change passwords for SQL Server services
  
• Change passwords for Central Administration and Timer service
  
• Change passwords for the Search service
  
• Change passwords for the default access account
  
• Change passwords for Shared Services Providers
  
• Change passwords for Web application pools
  
• Change passwords for single sign-on
  
• Change passwords for profile import

WSS

• Change passwords used for administration accounts
  
• Change passwords for SQL Server services
  
• Change passwords for Central Administration and Timer service
  
• Change passwords for the Search service
  
• Change passwords for the default access account
  
• Change passwords for Web application pools