I recently purchased a book called "Googlepedia" and it is a nice and basic explanation of SEO.
Seems PR, sitemaps, articles, blogs and content yes are more essential then the URL.
I have had several SEO companies suggest I create clean URL's with just the site name then the product, vs. the present ones www.website/store/cat16_product name.php (I have some lengthy hard to memorize ones for sure) but overall said better for visitors to remember the page not just for SEO. At present I am submitting to link directories, submitting my sitemap, verifying the site with google and hopefully just improving content is next. If what you sell many sell, then basically linking to quality ranked sites with similar content/products is key over URL's, or so I read, does anyone disagree?
I am new to this and having a hard time but sharing what I now know, not much!