I think you shouln't have quantity over quality... Obcourse there are popular general blogs and popular niche blogs that are just link filters, but in the end they don't provide that much useful content. The primary thing you should focus on when post/time is involved is scheduling and having a constant stream of quality articles. You don't need to post every day, just post on a constant plan... If you plan to post 3 nice quality articles a week, then go that root, and stay with it (not 2, but always 3)... Blog "self-spam" is the way of those who can't write well or don't know how to write and they find that the way of linking other peoples content is easier... In the long run, it isn't. Also, I know of a lot of readers who usubscribe to blogs that post very frequently because they just get overwhelmed with the content. Give your readers a chance to breath, and they will acknowledge this.
Bloggers like Steve Pavlina, Darren Rowse have come to numerous other business opportunities because they write great quality content and people recognize this... Be transparent, let the real you shine through the articles... Give some personal insight, because blogs are meant to be used in that way. Most people like to know who the author of the blog is. This can be a good thing isf you're really dedicated and love your topic, because people will start to respect you and see you as an expert on the topic. This is good business-wise, because you will become a brand. A brand blogger is very popular, because the mention of his name drives traffic. You can' do this with SEO, low quality posts and so on... You need to really be dedicated and work hard.
As for SEO, you should write for people first, computers second... If your content is as good as you believe it is, people will read it. You don't have to go out of your way at SEO. For new blogs, it really doesn't help. With the small amount of traffic a new blog generates, SEO won't get you noticed. As I said before, good content is the way to go. Why? Because content is king, and will always stay king. If you write something that people want to read (learn something, inspire someone, answer questions, ...) your article will be read, despite your table driven html site that has a crappy design and no keywords. I'm not saying SEO is unimportant, I'm just saying the SEO people have blown it out of proportions. The best SEO you can use is mod_rewrite, to make nice urls (site.com/article/name-of-article)... Other SEO methods will just hurt you and your readership in the long run.
James mentioned that having small articles if they are good doesn't matter. I want to stress something a little more. I think there are two main ways you can go, you can write short and sweet, or long and sweet.
In either case, the content has to be unique. Just don't go with something like copyblogger.com. I like that blog a lot... The only problem is that it's posts are too short to bookmark or print out and too long to just ignore. The problem I see there is that the author gives an answer to a question, but doesn't elaborate on it. Don't do that. If the reader is interested, he want's to know why... The why is important.
Lastly... You should make viral marketing and networking the main promotion methods of your blog. Use del.icio.us, reddit, Digg,... But DO NOT MISUSE because communities are good at getting back with people who want to "rape" the system. You should also network. You should see people in your niche as potential partners, not enemies. Help them in order to help yourself. Contact other bloggers, get tips, give tips,... You can get some really priceless information that way...
Well I think that's enough for one post...
