Great advice from Dan. I just wanted to add that we use getlisted.org to make sure the basics are covered . A really good tip is to use the GPS companies to make sure your business is listed correctly( Navteq: Teleatlas) . Also can't hurt to have your who.is info match your exact NAP (Name,Address,Phone) which has to be the same across all citations.
Also a tip for on-page optimization is the use of hcards you can see the documentation here Schema.org the major engines agreed to support this initiative. For non coders this markup can be produced here.
I'm rooting for your success. Hope this helps .
although the reasoning and application behind this is different than how I understand your intention . I have seen a lot of companies use a combination of /blog. /tech and /news to great success and I feel this might be relevant to your query. For SEO purposes I think sub folders will be a better choice as I feel your content is related. Definitely compose your blogs for the intended user . If you have the content go for it.