You can take advantage of Firefox's tabbed interface right from the get-go, setting it to open multiple, tabbed pages on start-up, a handy tool for anyone who likes to sign on to a few favorite Web sites every day. Click on 'Tools->Options' and the first thing you see should be the line for home page location. Click in the text field, and type in the page you want Firefox to load first on the leftmost tab. After the address, insert a vertical bar (|) and type the next address. There also appears to be no limit to the number of pages you can designate to open.
There's an even easier way to set up multiple home pages. When you're in Firefox, open all the tabbed pages you want to see on the browser's start-up. Go to 'Tools->Options' again. Underneath the home page location bar is a button marked 'Use Current Pages'. Click that and Firefox will automatically make all the currently open tabs your home pages.