https://support.mozilla.com/en-US/kb/Installing+Firefox+on+Linux

https://help.ubuntu.com/community/FirefoxNewVersion/MozillaBuilds

Thanks to The ed-meister for his references. They were helpful.

I find much of Ubuntu's installation instructions gibberish to my unknowing brain. For example, I don't know how to open a terminal or issue a 'sudo' command. Whazat?

I accidentally discovered that if I upgrade to Ubuntu 11.04(just appeared top line of the Update Manager in 10.10), I get Firefox 4 with it. The colorful icons on the left side are nifty, but the new desktop takes some exploring to find things. The main Navigation bar on the top of the screen is only seen when you mouse over it. And System Settings shows up if you right-click the little square icon in the top right corner.