When we talk about Drupal SEO, there are two things to consider one is about the relevant SEO practices and about appropriate Drupal Modules available. Optimizing your website for search engines is one of the most important aspect of launching & promoting your website especially if ranking matters to you.

Understanding SEO
For starters, you have begin with Keyword research and then optimize your content according to your findings by tagging, meta tags etc, Drupal modules once installed help you manage a lot of such parameters.

• Identifying the target keywords
• Using the Page Title and Token modules
• PathAuto configuration
• <H1> heading tags
• Optimizing Drupal’s default robots.txt file
• Etc.

While Drupal gives you a lot of ability to make your website content worthy & search engine friendly it is important for you to make sure you are not crossing the line or you could get penalized.

Modules Overview
Drupal Power is at its best when you have these modules & great brain working together. The basic SEO improvements can be achieved easily with the modules enlisted below, but you can win magical rankings if you use them logically & wisely. Understanding your keyword competition & enhancing your content is the basic key to success and ofcourse the modules:

Pathauto
Automatically create search enging friendly readable URLS from tokens. A token is a piece of data from content, say the author’s username, or the content’s title. For example mysite.com/an-article, rather than mysite.com/node/114 for every node you make.

NodeWords
Amazingly useful drupal module that allows you to create custom meta tags and descriptions for your nodes, which gives you the ability to target specific keywords and phrases.

Page Title
Enables you to set an alternative title for the <title></title> tags and for the <h1></h1> tags on a node.

Global Redirect
Manage content duplication, 301 redirects, and URL validation with this small, but powerful module.

Taxonomy manager
Make large additions, or changes to taxonomy very easy. This module provides a powerful interface for managing taxonomies. A vocabulary gets displayed in a dynamic tree view, where parent terms can be expanded to list their nested child terms or can be collapsed.

robotstxt
A robots.txt file is vital for ensuring that search engine spiders don’t index the unwanted areas of your site. This Drupal module gives you the ability to manage your robots.txt file through the CMS admin.

xmlsitemap
An XML Sitemap lets the search engines index your website content. This module helps in generating and maintaining a complete sitemap for your website and gives you control over exactly which parts of the site you want to be included in the index. It even gives you the ability to automatically submit your sitemap to Google, Yahoo!, Ask.com and Windows Live every time you update a node or at specific interval.

Node Import This module allows you to import a set of nodes from a Comma Seperated Values (CSV) or Tab Seperated Values (TSV) text file. Makes it easy to import hundreds-thousands of csv rows and you get to tie up these rows to CCK fields (or locations), and it can file it under the right taxonomy hierarchy. This is Super life saver module.