Normally, when you launch Outlook it opens to your Inbox. But perhaps you'd prefer it open to your Calendar so you can see what meetings you have today, or Tasks so you can review your To Do list on start up?
This is easy enough to do. In Outlook 2007, go to the Tools menu and select Options, Other, Advanced Options. Then select the folder you want in the Startup in this folder field:
In Outlook 2010, click File, Options, Advanced and select your folder choice in Start Outlook in this folder:
If you want to take it one step further, you can have Outlook launch whenever you boot your computer. Just create a shortcut for Outlook and copy it to your Windows Startup folder, which you'll find on the Start menu in your All Programs list.