You can find information about the relevance of directories to SEO by studying SEO more in depth. A good place to start is SEOSix that is a directory providing a comprehensive listing of useful websites for SEO
That is the million dollar question. Finding a "Good SEO Expert" is very hard. Many SEO companies are too large to handle their clients, give poor service and don't offer custom packages. In my opinion the best way to find an Good SEO Expert is through refferals, talk to your friends, associates and see who the are using, see if they are happy.
There are a few blogs that can give information about SEO hosting, such as articlerich. Some websites also give good and useful information about SEO hosting, such as webhostingtop.
The most secure and stable all-in-one tools access system at Group Buy SEO Tools
One can find more information about web optimisers from: Wikipedia, Web optimisers, Google Webmaster Tools, SEO Watch, Wojo Design, Webopedia, Web Presence Group, Top SEO Picks.
There are many places where one could find information on SEO. One could check online sites such as 'High Rankings' and other places for articles on the topic of SEO.
You can find out more information regarding SEO books online at the official SEO book website. You can also find reviews for most SEO books on Amazon where people will tell you their personal experiences using them.
"Yes, you can find Seo Advice on twitter. Their username is @seoadvice. You can search for seo advice on the twitter website and you should find it easily."
I advise you to read a couple of good articles on SEO from a trusted source. Then possibly find a company you are comfortable with and then execute and critique your plan.
One can find a good SEO software on SEOBook website, IBusinessPromoter website has a list of top ten softwares of this kind and also tells where they are downloadable.
I recommend learning online. I'll find a lot of information and training courses. Good luck.
The June 2010 issue of Inc. Magazine had a very informative article about selecting highly effective SEO keywords. Among their suggestions was to avoid vanity keywords and to focus on good phrases.