These are the tools every Search Engine Optimizer cannot do without, the basics of the basics.
You don't need to start using Google Adwords to take advantage of the Keyword Planner. Just open your Adwords account and start using it!
This should be the first tool you use to check if the keywords you are thinking of ranking for are actually searched by internet users. It will also throw up other suggestions you might not have thought of.
Set up your Google Adwords account at https://www.google.com/adwords/.
This free to use resource is essential.
Set up your Google Webmaster Tools account here.
Another essential and free resource.
Set up your Google Analytics account at https://www.google.com/analytics/.
Open your site in Google Chrome and then press CTRL+SHIFT+i to see how your site looks in a variety of mobile devices and tablets. Search engines consider how mobile friendly sites are when ranking them for searches carried out on mobile devices so make sure yours doesn't fall apart on a smartphone or tablet.
Get Google Chrome for free at https://www.google.com/chrome/
If you're techie minded this duo is for you.
Firefox has built in analysis. Just right hand click anywhere on a page and select 'Inspect Element' to see the HTML code and CSS behind that part of the page.
The Web Developer Tool Bar for Firefox by Chris Pederick adds a slew of extra tools from rulers to image checking to resizable windows so you can see how your site might look in different screen size.
Get Firefox for free at https://www.mozilla.org/en-GB/firefox/new/.
Get the Web Developer Tool Bar http://chrispederick.com/work/web-developer/
Take control of your meta tags with the industry favourite if you use WordPress to host your content.
The Yoast SEO plugin can be found at https://yoast.com/wordpress/plugins/seo/
This is a tool you download to your computer which will then crawl your site (or any other site) in search of broken links and a whole host of SEO issues.
This is third party software so use with caution. Some of the issues thrown up are questionable as this is just the opinion of the programmers rather than the official Google or Bing line.
Many of the problems it flags are also shown in Google Webmaster Tools so check there first to see if Google itself is complaining!
You can pick up screaming frog for free at http://www.screamingfrog.co.uk/seo-spider/
I'm Tim Hill, a Search Engine Optimisation and Online Marketing specialist. I created this site to help others understand that SEO is not a mysterious black art!.
If your a newbie try the Getting Started in SEO page, otherwise feel free to dig around and learn more.