Use tabs as your home page in Firefox
"Is there a way that when you open Firefox you can have multiple pages open upon start-up of the program? In other words having multiple home pages?"
Go to Tools, Options in Windows--or Preferences in Mac OS X.
In the main section, go to the drop-down menu "When Firefox Starts" and choose "Show my windows and tabs from last time."
Now every time you launch Firefox, it will give you all the tabs you had when you closed it.
But, if you want a defined set of tabs every time, no matter where you left off, you can do that, too. Thanks to Shameer for the easy tip on this.
First open up the tabs you want to use as your home page set.
Then, go to Preferences in OS X--tools, then options in Windows.
Change the drop-down menu to "Show my homepage."
And then press the button "Use Current Pages." You should see the URLs for all the pages you had open listed in the text box marked home page. Each URL is separated by a pipe symbol. That's the one that looks like this: | Handy to know if you want to make a quick edit to the list later.