Do some key word research. Figure out what your trying to target, and do your own home work on domain names. Then when you write text for the blog, use those key words as often as you can. In other words, if you decide to build a blog about blonde teens, buy blonde-teens.com, and use the text "blonde teens" in every paragraph.
Wordpress is the way to go. Everyone uses it and there are a lot of tutorials about it.
For design, there are tons of places that give out free designs.
Exactly. You don't put bukakke on a celeb blog.
You have to update often, and I'd update with at least three hundred characters. I spend an hour or two a day just writing my own blog posts.
I use Blogdesk to write my posts (
http://www.blogdesk.org/en/index.htm). It's a little free program that allows you to write blog posts - No need to log into wordpress every time.
There are dozens of ways to drive traffic to your site. Google sitemaps, link trades, free blog directories, link lists, SEO plug ins, etc etc etc. However, every link you put up on a blog dings you with Google, and too many dings and it's hurting you. At this point I just build blogs, do the usual SEO tricks, but never do link trades or what not. Just pure organic at this point.