The most important aspect of search engine optimisation is keyword research. If you are not targeting the right keywords you will either get no traffic or get the wrong type of traffic. Also important are lots of links (with keywords in anchor text) and a good amount of keyword specific content. Usually about 300 - 500 words per page with your keyword being mentioned between 3% and 5% of the time.
Use this link to find a long list of relevant keywords (can't post links yet so just search for this tool);
Free Keyword Suggestion Tool From Wordtracker
And the google keyword tool is good for finding out a rough idea of each keywords search traffic;
Google keyword tool
Also install google Analytics as this is very useful.
Joomla and wordpress both have the ability to do well in search engines, search their forums for
SEO to find out how to tailor them specifically. Stay with the names in url instead of numbers.
Also keep you blog and website separate (on different servers if possible) and market them separately giving links from your blog to your main website. I wouldn't link from your main website back to your blog though as this may devalue the links from the blog slightly (just my opinion though).