The base of really good link building is getting people to link to you, not going out trawling for places to put links. These links can be of a much higher quality than the ones you'll get from forums and blog comments.
Write an article, make it in-depth and useful. Then submit it to article repositories and include a link back to your site. There are hundreds out there, and there are even tools that will reword your article and automically get it posted on many of these sites. See my piece on Article Spinning for more info. Especially useful if your website is article based, as you've got the content already done!
When I worked at Diseño Earle last year, our team designed an Eco House. With eco-architecture being such a hot topic I drafted a press release and sent it out to 4 prominent architecture blogs. We were featured on all 4 of the blogs within a couple of days and got prime position links from those high PR sites. Within the following week we ended up being featured on over 200 other architecture, design and eco blogs and gained almost 400 links. Not bad for about an hours work! You have to have something exciting though, and you need to write your press release well. But for very little effort, the results can be staggering.
Check out what I wrote about Blendtec and their Will it Blend phenomenom as well. A great idea can spread like wildfire throughout the web and can bring some astonishing results.
Link Baiting sounds a little ominous, but its a very fair and valid method of getting links. Link baiting involves producing a really useful utility, or a fun game, or just some great content, that people can put on their site for their visitors or simply link to. A great example I've seen around is a Foreign Exchange calculator. Very useful to a multitude of websites and normally well placed on a page when used. Other examples include Flash Games, Top Ten lists, viral videos. How-to guides are also a great idea, these can be great resources and if they're good, they'll get you links. Good, solid natural links, just as Google likes them.
Writing off-site content can be very useful. Very now, very hip, very web 2.0. There are many sites that allow you to write the content - wikipedia is the biggest example of user-generated content. Squidoo provides a great platform for placing off-site content. I've seen a Squidoo lens about some smoothie recipes with PR of 5, so make a lens, make it useful and people will link to it. Put your links in your Off Site content and reap the rewards!
As you can see, the point of all of these is KILLER CONTENT. The better your content, the more interesting your content, the higher the likelyhood of you gaining great links is. And it's with these great links that you're going to see the best results.
As of Monday, I'm going to be doing a case study of Inside Out Health Magazine's website, which is owned by my friend James.. I'm going to take the site through a complete SEO plan from start to finish. It's a great site, with lots of high-quality content so there's lots to work with, and hopefully it should give all of you some great ideas on how to organise successful SEO campaign.
Have a great weekend!