a) The most trusted way to build links is from Sites those have high page rank. If possible try to get a link from those Blog or sites which rank high in the Google search. These web site will boost your SEO Strategy. You can also create link from your own site by linking your own post from new post thereby making sure that more link point to your blog. Remember there are thousand of new blog daily coming up therefore you need to consistently doing this activity, why because 90% of blog which start in hope of making money get shut down in a year or two. Therefore make sure you do it better than other and attract lot of traffic. Try some software for FREE TRAFFIC
b) Article submission is the Next best way to get good link. You can use many of those available sites, like ezinearticles, Amazine, Go Articles, these are top article directories online. How you know, just create a good post for them and post it and include your blog link in that post. Also these article directories gives you link as about author in the end. Just be ready and write as much as possible.
Few more Additional Tips
Also try to write such post which can be shared by many people. These is also termed as link bites. Create interesting link bites for these and you will yourself see the effect of it in later days. Using the same technique you can also create social networking.
Allow your post to be shared in Face book and Twitter. These Social networking sites are very helpful for your site/blog. The more your link are shared the more you create link to your site the more improve your PR rating and SERP.
If possible try to get link form .org and .edu websites. Normally these are non commercial websites and Google gives then due weight age. If you create link from those website take it in writing that your page rank will improve drastically.
Always remember don’t go for purchasing links because they attract lot of spam and when you leave then your rank will degrade badly and Google can understand that.
Implement these and see the difference.