Listed below are the most important factors that makes a web site efficient and effective. Of course, some of these factors are technical, but some important visual and functional guidelines are also included.
Slow load time will defer a spider from your site, not to mention your visitors. Flash intros should be never used, otherwise, why making users have to click the famous "skip intro" button for? If you are getting a business web site, don't get an intro!
The maximum loading time for every page of a web site should be kept within a very low profile, below 2 seconds on a cable connection. How to get that? Well if you follow all these instructions herein, you will achieve that.
Your web design should be soothing, enjoyable and appealing to the human eye. It should never be visually polluted, busy and confused to navigate.
Your pages and your site as a whole should be neat, clean and organized. The design and organization should be consistent through all the pages.
Your web site should must be compatible with all browsers (Internet Explorer, Mozilla, Opera, Safari), make sure it works properly on Internet Explorer 6.0 and 7.0.
Approximately 3 years ago, Internet Explorer was the most used browser in the world, with usage rates above 90%, but recently, Mozilla Firefox, which is based on the today's open source Netscape 9.0 platform supported by AOL-Netscape, has taken a considerable partition of the usage rate in PCs and Macs.
At version 7.0 of its internet browser, Microsoft have reached good standards of XHTML and CSS rendering at strict mode. The two most used browsers in the world can finally render web pages the same way and this is definitely a great achievement! In any case, considering a cross-browser web design is always very important.
The home page is the most important page to be indexed by the crawlers and is the first impression that a user gets from a web site. Its information content is crucial and will determine success or failure. As mentioned by the Educational Theorist Edgar Dale, "There is one thing worse then not communicating. It is thinking you have communicated when you have not."
All images should be optimized for the smallest possible file size. JPGs are the best and can be very well optimized without loosing quality, Photoshop does the work. GIFs cannot be optimized and should only be used for small icons where gradients are not applied. Large image files will severally slow loading time for the regular users and for the robots too.
It is a must that the web site design incorporates your company logo, otherwise it will look like an adapted template done by an amateur.
Your HTML/XHTML code should be clean, clear and robust, errors-free, tableless, W3C compliant and without inline styles (a CSS file should contain all styles). This will make your content appear to be more prominent throughout your pages and will make it easier and quicker for a search engine spider to get through your pages.)
Well here it is one of the main reasons why a web site gets stuck and never gets optimized. Java Script menus should never be used! Spiders can not read Java Scripts, can not crawl links in Java Script, and it gets in their way making, sometimes, your most important text appear to be less relevant. If you must use Java Script, move it to an external file.
Be judicious with frames, or, to be safe, avoid them completely. A complex frame structure confuses many web crawlers. Frames were banned from 1.0 strict and that's one of the reasons why it is the best Doctype, frames create bandwidth to other's web sites without showing the content it was supposed to show. The frames functionality can easily be replaced by the usage of the require or include PHP tags.
Image map is the function of placing one single image divided in several areas that generates different links. Spiders can not crawl the links within image maps. Do not use it.
Make sure that your site does not have any links to missing pages. Spiders and editors will be very critical of this.
Search Engines will not index flash sites. Therefore, unless your flash site gets very popular (and obtain a large amount of external links) it will not get high ranking no matter what. Only businesses that can afford PPC should consider using Flash web design. In addition Flash requires a lot of resources and may cause slow loading time.
Your web site must contain actual text, which is the only thing that can be indexed. The same way spiders cannot index flash, they will not be able to index images. The only content that can be indexed from images is its file name and its title tag, make sure all your images have a relevant file name (not img001.jpg as an example) and that it has a title tag that uses 3 to 5 words.
Obviously, one important key of all search engines is to bring relevant content. Imagine how useless Google would be if all the results out of a search, leaded to web sites with exactly the same written content. Therefore, most of crawlers added a very smart duplicated content detector tool to their robots, so it can easily detect new pages, brought up to the internet, with content copied from other online sources. Those pages will be placed as irrelevant immediately.
It is ok if you copy a small percentage of your content from other few web sites, but more then 50% (at least) should be unique content written by you.
Do not buy "content packages" offered by some SEO companies because it WILL NOT help you. Unique content is not found for sale, it has to come out of peoples brains and must be typed in, not copied. If you implement your site with content that were copied from other web sites, you will immediately have it placed in the irrelevant results list. Irrelevant results do not come out on a search unless its requested by the user.
Sounds and Animated Gifs can be annoying to some visitors, don't overuse it.
A big mistake that most webmasters and web designers make is placing pages that includes words such as "under construction." This is a terrible practice that gets picked up by most crawlers and should not be used. After all, what kind of impression you think this will give to the major crawlers? I am sure that this is very annoying to the users that find themselves leaded into a dead or undone web page. Any undone web page should be kept offline and uploaded only when it's done, it's that simple.
Including small or tiny text, or text with the same color as the background color (so it turns out to be invisible by the users) is considered spamming, and will most likely lead your domain to be banned from most crawlers. Googlebot is a very detailed program capable to identify all common spamming techniques. Be aware of that! To make sure that your pages do not contain this type of content you can select all the contents of a page (click on the "Edit" menu of your browser program and then click "Select All") and make sure you don't see some highlighted content that wasn't there previously.
Some web designers place links pointing to their own sites on every page of their client's site. In this case, the crawler's robots will count one link, from your domain, to your web designer's domain, on every single page of your site and will assume that your site is nothing more then a sub-site probably owned by your web designer. Any page rank earned by your domain will eventually be transferred over to your web designer's domain and your site will never be optimized due to the fact that it has too many links points to another single web site (in this case, your designer's web site). This technique is, at least, unfair, from web designers and I have seen web designers practicing it over and over. It is very fair and professional if your web designer places only one link to his site in your home page and nowhere else.
To learn more about efficient and optimized web design please review my search engine optimization documentation.