Decreasing Your Page Load Time
Page speed or page load time is something that shouldn't be ignored when optimising your website for user experience and SEO. The page load time is an important factor for SEO because your website receives a rating from search engines based on your page speed. The slower your page loads the worse the user experience, thus a worse rating from the search engines. It's in your best interest to do everything possible to reduce the page load time as much as possible because it could mean the differnce between a potential customer purchasing your product or service or leaving your site. There are a few factors that come into play when looking at page speed, the ones I can think of off the top of my head are:
1. Hosting
Having fast, reliable hosting is vital to acheiving a good page speed. If you want the best page speed then make sure to avoid shared hosting situations on overloaded servers and try to host in the same contoury as your customers are if possible. If you're going after a worldwide market you will want to use a distributed hosting service like Amazon Web Services which will serve up your website from multiple locations around the world if set up correctly.
2. Image compression
Make sure to compress your images as much as possible. Image compression is built into almost every image viewing and editing application out there however is rarely used correctly or to it's full potential. If you compress an image correctly you should be able to acheive a fraction of the file size without causing the image to be too noticably different in quality. Below is an example of two images, the one on the top is uncompressed weighing in at a file size of 168KB. The one on the bottom is compressed at a file size of just 48KB - over 3 times smaller. The difference in quality is negligable however the affect on page speed is very noticable especially if your website has many images / graphics on the one page.
Uncompressed
With Compression
If you don't know what tool to use for image compression here's a few that I use reguarly. Results vary with each.
+ Preview - Mac's own stock standard image viewer/ edidtor
+ Pixelmator - A great application you can pick up from the app store for a fraction of the cost of photoshop
+ Photoshop
+ Gimp - an open source image editor
3. Caching
Enabling browser caching for your site elements such as images, css and scripts can go a long way toward increasing your page speed. There are different methods for caching and the rules for browser caching are set on the server side generally by eneabling expiration timeframes which will tell the users browser how long to cache a particular page asset for. Before you begin caching elements on your page you will neeed to analyse your page and determine which elements won't be changing reguarly. Some examples of elements that won't be changing reguarly include, your favicon, logo, most css and scrip assets. The type of caching implementation you use will depend on your web server type. Web servers running apache will most likely use .htaccess caching while Windows IIS allows you to enable caching from the http headers tab from a site in IIS Manager.
More info on enabling caching for a site in IIS here: http://stackoverflow.com/questions/1994223/leverage-browser-caching
An amazing tool for generating a site page speed performance report is gtmetrix.com. There you will be able to enter your site URL and receive an almost instant overview on your page perfomrmance with reccommendations on what you can do to optimise your site.
4. HTML, CSS & Javascript size + Referencing
Although the size of your html, css and scripts are usually miniscule compared to the rest of your web assest they do make a difference. To reduce the size of these elements you can minify them. This means getting rid of any unnessessary characters such as excessive spacing or hard returns and using short tags. You can minify code yourself or you can use a free tool like http://www.willpeavy.com/minifier/to do it for you automatically.