Looking to bolster your site's search engine coverage on a shoestring budget and need a helping hand?

Fortunately the web is awash with SEO tools and resources, but it pays to do your homework first and pick your kit carefully. Just like the practitioners within the search marketing industry itself, there's the good the bad and, well, the ugly. We recommend 10 of the best free tools.

1. Google Webmaster Central
Even if you're not headstrong on SEO, whatever the size of your site or blog, Google's laudable Webmaster Central and the myriad user-friendly tools under its bonnet should be your first port of call. The suite of tools gives you valuable information about your site at a glance: it can assess your site's performance and observe potential problems to troubleshoot, help you ensure your site is Google-friendly and monitor Google's indexing of your site. You can even report spam and request reconsideration if your site has incurred a penalty. Plus, if you don't refer to their Webmaster Guidelines now and again, well, you've only yourself to blame if you go wrong.

2. Google Analytics
It's all very well having prominent rankings, but if you don't understand what your visitors are doing once they reach your site, you won't make the most of your SEO investment. Use Analytics to evaluate your users' behaviour and geo-trends, observe bottlenecks, identify popular search terms and benchmark yourself against conversion goals. Oh, and you might also like to read our Complete guide to Google Analytics.

3. Yahoo Site Explorer
Yahoo Site Explorer lets you access the information the company has about a site's online presence. You can see which sites and subpages are indexed by Yahoo Search, track sites that link into webpages and view the most popular pages from any site.

4. Google Keyword Tool
Knowing the right keywords to target is all-important when priming your web copy. Google's free keyword tool couldn't be easier to use. Plug your website URL into the box, start reviewing the suggested keywords and off you go. Jill Whalen, CEO of HighRankings.com is a fan and offers advice to those new to keyword optimisation: "make sure you use those keywords within the content of your website. It's really a question of being descriptive as keyword phrases typically describe what you offer. Think about the fact that you're trying to answer someone's question at the other end of the search engine. They're typically searching Google because they have a question or a problem to solve. Make your website answer those questions and solve those problems and it will be the one to show in the search results."

5. Live Keyword Analysis
Any seasoned search engine optimisation specialist will tell you keywords matter, and while simply clawing keywords into your text arbitrarily can do more harm than good it's worth ensuring you have the right balance. Live Keyword Analysis is a breeze to use: simply type in your keywords and then paste in your text and your keyword density analysis will be done on the fly. Don't forget to proof and edit your text accordingly for optimum readability. A must for website copywriters.

6. Online Sitemap Generator
Not to be mistaken with that all-important HTML sitemap page, XML Sitemaps is a fantastic free tool that lets you create an XML sitemap of all your pages that can be submitted to Google, Yahoo and other search engines to help them crawl your website better. It's easy to use and every website owner should do this as a matter of course.

7. SEOQuake
According to addons.mozilla.org, SeoQuake is the number 1 SEO toolbar extension, with over 447,000 downloads as of February 2009. SeoQuake allows you to view multiple search engine parameters on the fly and save and compare them with the results obtained for other projects. Although the icons and numbers that SeoQuake yields might be unintelligible to the uninformed user, skilled optimisers will appreciate the wealth of detail this add-on provides. Gauge details about number of visitors and their country, get a site's traffic history trended on a graph, and more. The toolbar includes buttons for a site's Google page rank and index, Yahoo links and link domains, MSN index, Alexa ranks, web archive age, Delicious index, and a link to the Whois page.

8. SEO Book's SEO Toolbar
SEO for Firefox is another data-packed Firefox add-on, making it easy get a more holistic view of the competitive landscape of a market right from the search results. In addition to pulling in useful marketing data, it also provides links to the data sources so you can delve deeper into the data.

9. Google Website Optimizer
SEO isn't all about rankings. Without the right balance of content that engages with your visitors and drives conversions, you're earnest optimisation could be wasted. Website Optimiser helps take the guesswork out of the game, allowing you to test your site's content: from simple A/B testing of two different pages to comparing a whole combination of elements on any given page. In order to run some of the more complicated multivariate testing, you will need adequate traffic and time to make the results actionable, just as you do with Analytics.

10. WordPress
Ok, so it may not be an SEO tool as such, but if you want a ready-made search-engine friendly platform - in many instances, as good as any self-starter website - then WordPress is arguably the best blogging platform available. It's OpenSource, and claims to be the largest self-hosted blogging tool in the world. If you want to know more about SEO for WordPress, here' s a great blog to get started with.

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