Using one-way link building for SEO is the most important factor for getting highly ranked page results. Google for example gives page results based on the popularity of a link, the page rank of a link, the authority of the link and the relevant pages linking to your site.
Tip #1 (Popularity)
What your website really wants is a consistent amount of natural links that is gained over a period of time. This ensures your site is growing consistently and proving to be popular. More to the point, you need to gain links from other popular sites including high alexa ranked sites. Just go to alexa.com and view the top sites that you can join and contribute on. Some maybe yahoo answers, Wikipedia or any site that can drive some branding to your site.
Tip #2 (Page Rank)
The quality of your PR in those sites you are linking with must appear natural to various search engines. You must choose and link websites carefully with high PR preferably 6,7,8 & 9+. You need also to seek more links from a good range of websites with both high and low PR values for the links to appear natural.
Tip #3 (Authority)
Gaining links from .gov .edu sites are all natural methods that happen over time. Other methods of authority are local community sites and charity organizations. You also want to have blog reviews and forum posters naturally saying that your site is great and posting links to your site in social communities. Articles and press releases are also a great way to gain authority.
Tip #4 (Relevancy)
80% of sites that link to you should be relevant and should be from relevant content pages. You want to continually seek partnerships especially when starting out. Gaining a backlink from a directory for example from a relevant category pointing to your site is a proven relevant link. This is just 1 example of many relevant links you should be looking at gaining.