Here is how you can change the default home page location in Firefox and everything you can do with it.
Go to Preferences (normally under Edit or Tools menu) and click on Main tab.
Here you can do several things:
Simply empty the textbox titled Home Page and save it (by clicking on the Close button) to have no page loaded on startup. This makes your startup faster. Normally I use this option.
Click on Use Current Pages button to save all the pages currently opened in your browser tabs to be opened every time you open your browser. This is a powerful feature. Suppose you want to open your corporate home page, your browser based email (like GMail) and your brokerage account every time you open the computer. Open all of them in browser tabs and then use this option. This will ensure that all your favorite pages are opened every time you open your browser. This is a big time saver.
Restore to default restores the default settings. In my browser it just empties the Home Page textbox. This is, in my case, equivalent to the first option of not loading any page on startup.
Use Bookmark is another interesting feature. You can use this to select any bookmark to open on browser restart.