going to tell him to concentrate on content and building it up with lots of pages before worrying about google etc

I hear it helps to buy an old dead site and ressurect it, as they will already have lots of indexy thingymabobbies done on it by search engines, than starting off a new site from scratch. I've heard it said that there's no point SEO-ing anything under 6 months old. kinboshi I'm sure can tell you if there's any truth to that.
It is certainly easier to get a site ranking well if the domain has been around for a while and has been indexed and ranked by Google previously. But there's nothing stopping you getting a brand new domain and getting it to rank strongly within 6 months - it'll just take a bit more effort and money. If you can afford to be a little patient then that helps.
Because SEO doesn't produce overnight results, many will use PPC advertising to generate traffic in the early days of a site - but that can be prohibitively expensive in some markets.
With blogging, if you're looking to build an audience then realistically, the only way is to read and participate in others blogs and keep doing so for the ones who reciprocate. It's not a case of if you build it they will come, you have to go out and get them, do unto others as it were. If that's not something your friend enjoys then I wouldn't bother with blogging.
There's plenty online blogging community sites and initiatives to put you in touch with other bloggers and wotnot. Obv best to concentrate on blogs in your niche or related niches.
This is applicable for both personal blogs, and ones with some sort of commercial or buisness purpose.
Natural traffic (of people who actually might read your site, rather than dodgy schemes to get junk hits) from search engines only can only be expected from bigger established blogs. To get there you have to do the whole blog reading thing yourself to get your own site active and happening. If your content is quality then word will gradually spread, people will recommend you for this that and the other.
Writing something and expecting the world to come read if you just do a bit of SEO, and nothing else, will just be a source of frustration. Not saying that's what your friend is expecting (indeed, how would I know?) just giving some general advice.
Yep - if the content's good and you're respected for what you're saying by your target audience - you'll get the traffic. A committed blogger will use twitter and other social
notworking networking sites and tools to promote the blog and drive traffic. SEO is certainly an important element in generating traffic and shouldn't be overlooked, but it's not the be all and end all for a blog.
I don't know how much time and effort tank spent on educating himself about SEO, but it sounds as though he's done his homework and knows a lot more than many marketing people who should know more than they do. I'd recommend your friend does the same. Unless of course he has loads of money and wants someone to do it all for him
