This may not work for everyone but it's done me well... I left work almost 6 months ago and not looked back.
My main site is a blog with several video courses as products.
So here's how :
My main site started life as a blog around 2 years. Back then all i really did to promote it was post some links up on forums whenever there was a new post (around 1 a week). Over time it started to grow as i was adding more and more content and pages started ranking.
Where it really exploded was when i started to outsource the content generation which meant 3 or 4 posts a week. Of course from day 1 i was also collecting email addresses which now amount to around 26,000 all laser targeted for the niche so any new products that go up i have a ready audience.
Through on page and off page SEO i've pretty much sown up google rankings for a load of key words for the niche so i'm getting a couple thousand visits a day - and it's still growing... i have 3 sites now with another 2 in the pipe to launch very soon - my team is now 6 people creating content and working on promoting the sites on various forums and off course the big one outside of Google is Facebook...
I kick started of the Facebook audience with paid ads which got me several thousand quite quickly - all those ads were for likes for the FB page rather than sell them or push them to the site - i'm happy with the likes as every new post that goes up they see (well some of them, i believe FB only lets a 3rd of your fans see the content you have to pay for the others to see now)... a soft sell to them and never try the hard sell on them. I hope they click through and sign up then i have them into an autoresponder chain of free content and eventually i sell the courses.
Seems to work!
So in short I would make set up the blog and don't worry so much about monetization at first - build up a loyal audience and from day 1 capture emails and Facebook likes (I use the WP plugin popup domination to collect emails - people don''t like popups and as an advocate of user experience i generally hate them also ... but my sign up rate tripled when i added that so i'm not complaining here!).
Forum marketing is a great way to build a fan base - the trick to this is to search for high traffic forums in your niche and never be selling. Simply answer a post a day on each forum as helpful as you can and just make sure your site link is in your signature. Over time this will make you an authority - and that's really when the magic happens...
When they sign up on your site offer them something for free - a report or video or something and then set up 5 or 6 email auto-responders to go out once every couple of days (actually what this is doing is building trust but also getting them used to you mailing them every other day - great when you start selling products!)
Try and post every other day and make sure the link to that post goes out through all your channels - FB, Google + or Twitter - whatever you are using... but be consistent.
Slowly add in monetization - affiliate program is probably a good starting point although the end goal would be your own products and have your own affilaite program!
I'd avoid adsense or 3rd party adevrtising - you are essentially sending traffic to your competitors for a few cents. When you have the ads on your site should point to your own products!
I send out 3 emails a week to each of my lists. 1 is a newsletter roundup of what's been on the site, 1 is a sales email and 1 is a 'thought of the week' when i give a little ramble about something in the niche. Seems to work and my open rates / clickthroughs are steady around 23% and 37%
As your site is growing SEO is ultra important - and this will also benefit from a clean WP build and some solid use of tags/categories. In terms of actual on page SEO try the Yoast plugin on WP - best one i have found (even has a google keyword suggester built in and a little checklist to show you how well the page will perform).
Split test everything - even a simple change in headline can double your conversion rate.
Analytics - I study my analyitcs in great detail once a week. Lots to learn there about your customer habits.
I use hellobar to drive traffic or to increase sign ups - works very well.
Customer service - I still answer each and every email i get through the site personally. It makes a big difference i feel to actually have a real person answer and speak to them directly. I feel this is a big part of why my websites worked out the way they did.
And finally - really it's all about the content. If you offer great value and excellent content you will become an authority in your subject and you will have people begging to buy your products! It's worth in some point at the end of your autoresponder chain to actually just ask the sign up what product they actually would like to see - pretty much all of mine came from doing so and the result is a lot of happy customers!