A robots.txt file is a file on your webserver used to control bots like Googlebot, Google’s web crawler. You can use it to block Google and Bing from crawling parts of your site.

If you are serious about organic search engine optimisation, forget about using, or optimising frames and read up on the latest guidelines for SEO.

Do not use access keys. The access key attribute, introduced in HTML4.0, is intended to provide keyboard shortcuts in that they provide an alternative form of navigation. This addition allows users with limited physical capabilities to navigate the organisation’s website more easily. There are some drawbacks with website access keys, for example: functionality depends on … Read more

How to design your website for users with disabilities.

No. While Google recommends we use W3C validation, Google doesn’t rank valid html and css pages above invalid pages. If Google can crawl and render a page Google will rank the page appropriately based on how relevant it is to the query. Invalid HTML can on the other hand can cause search engines problems.