What I'd recommend before upgrading is make sure you have a second, separate browser set up beforehand such as Firefox, Chrome or Opera and just make sure you don't set it as the default browser so it won't affect Internet Explorer. It means if anything goes wrong with the Internet Explorer upgrade you don't lose the ability to browse the internet which can be essential if you need to fix a problem, I'd always recommend having a backup browser as several times I've been asked to fix a machine where IE has broken and it's a pain without a browser unless you have a second, connected PC handy.
John