When you create a custom post type, you should edit this option for setting you post type menu in admin:

This list is very usefull. It represents a hierarchy preset of menu elements in WordPress admin menu:

• 5 – below Posts
• 10 – below Media
• 15 – below Links
• 20 – below Pages
• 25 – below comments
• 60 – below first separator
• 65 – below Plugins
• 70 – below Users
• 75 – below Tools
• 80 – below Settings
• 100 – below second separator