The best speed tests are free, and found at
http://broadbandreports.com -- the original, biggest and best site for user-to-user ISP support. They can also help you compare your speed with others using the same ISP and in the same area, and give you advice on speeding up your browsing.
The simplest thing is to adjust your caching. When you visit a web page for the first time (like this one here at BigBlueBall) your browser has to download lots of files. There is the HTML that makes up the page itself, the CSS, javascript files, and usually lots of images. Many of these files are the same from page to page within the same web site (like the logo, for example). Your browser will "cache" these files, storing a local copy so when you return to the page, or when you visit another page on the same website that uses the same files, it doesn't need to be downloaded again.
In Internet Explorer, check your cache settings by going to Tools > Internet Options then click Settings under Browsing history. I recommend using the "Automatic" option. If you pick either "Every time I visit the webpage" or "Every time I start Internet Explorer" it WILL slow down your browsing. On the other hand, if you pick "Never", you will sometimes miss stuff that has changed (like a reply to a post in a forum). Automatic is the best option.
There are lots of other tweaks you can make, and for those, I'd suggest that BroadbandReports site.