I use Google Keyword Tool to define generic and long-tail keywords, Keyword Snatcher to dig into Google suggestions for more long-tail keywords which people actually use when searching. As a result I create a list of primary and one or more secondary keywords for each page.
keyword density, keyword proximity, keywords in page title, meta tags, text headings (h1, h2, etc), text body, image alt text, link anchor text, keywords in bold and/or italic. I use SEOMoz's On-Page Keyword Optimization Tool (formerly Term Target) to check the on-page optimization score.
I use Google Webmaster Tools to check for crawl errors, duplicate page titles and meta descriptions and then 301 redirect 404 pages when needed, remove duplicates by changing the content or using canonical URL tag.
Link Assistant (link-assistant.com) to organize and track link exchange or link buying, to find potential link partners through search engines and competitors backlinks
Fast Blog Finder to discover topically related blog posts and receive some link love via relevant comments
building a network of satellite sites (is in fact part of link building)
either build it on free publishing platforms such as blogger.com or wordpress.com OR, preferably, create sites on paid hosting with your own domains
produce unique relevant content for each site
interlink the sites/blogs in a non-reciprocal way to flow the authority and link juice towards your flagman site(s)
update sites with new posts, thus you can use the network to promote new projects
Content Research and Copywriting
I'm experienced with writing search engine optimized promo articles on virtually any topic
I use Power Article Rewriter and TheBestSpinner to spin articles to create unique variations of texts for satellite sites (60-90% uniqueness)
Tracking Site Metrics
I use SEOBook's Rank Checker (Firefox plugin) or Link-Asistant's RankTracker to track search positions for multiple projects/keywords
Link-Asistant's SEO Spyglass or SEOMOZ's Open Site Explorer (formerly Linkscape) to research competitors backlinks and other site metrics