SFDC Dev 401 Exam Important topics

• Master-Detail / Lookup / Hierarchical relationships
• Report / Report Types 
• Dashboards
• Org-Wide Default
• Sharing Rules
• Approval Processes (Unanimous / Parallel / Skipping Steps / Dynamic Routing)
• Junction Object
• Data Loader / Import Wizard
• Formula Fields
• Analytical Snapshot
• Workflows
• Encrypted Fields
• External Ids
• Governor Limits

Cheers!!!