If you are running a WordPress blog, you might be interested in reading further. Note that these are my answers and you could have your own opinions. But, anyway…here we go:
1. What is the best url format for a WordPress blog?
I guess this could be a very popular question. As you know, WordPress allows users to output blog post urls in different formats such as /%parmalink%/, /%date%/%permalink%/, etc. Well, from my experience, url formats do not matter much in having higher rankings. But what I will always recommend is, try to do some deep links (ie. 2007/05/06/blog-post.html). Search engines love deep web pages and if all your blog posts are placed one level under root (ie. .com/blogpost/), it might look a bit abnormal. Some people prefer to have /?p=5 format, which blog posts are accessed via dynamic parameter. The good reason for doing this perhaps is a higher PageRank post (if your homepage PageRank is high enough).
2. How often do you think I should update my blog?
Updating is the key thing in running a blog, whether you are writing unique content or copy and paste. Search engine knows if your website is static or a blog, or a forum. What happens if lack of update? What I can say is, you should expect a drop of PageRank.
3. How can I get a higher PageRank value for my blog?
It’s easy to get PR3, PR4, or PR5. But anything higher requires further input. Unique content is definitely required. Besides backlinks, long unique blog posts can help pushing your PageRank further.
4. Should I worry about setting unique keywords and description tags for each page?
Meta tags do not give you a better ranking, especially the meta keywords tag. The only thing is the description tag could give your ranking a better looking description, that’s all. Setting unique keywords and description for each page, is a no need. However, good title for each page is extremely important.
5. Should I place a link to the theme owner or even WordPress?
I do recommend that you do so, although it does not do any good or bad in terms of seo. It is a good way to respect the intellectual property on the Internet.