Before you do anything to speed up your web site, the first thing you need to check is, how well it performs. If you don't do that, you won't have a baseline to see how the improvements you make are affecting the loading time of your site. With this baseline you can check if the change is really an improvement, or if it is slowing down your web site. So, let's start getting that baseline.
Using the OctaGate service, you can perform the first check of your site ( http://www.octagate.com/service/SiteTimer/). Once you get there, just fill in the link of your web site.
After you hit the Start button, you have to wait for a few seconds until the page is completely loaded. After the check is done, you get a full view of what is using up your download time.
In the following screenshot we can see what each color code represents:
Let's look at the meaning of each color code:
The first block shows when the element in that line is called
The second block...