Contact others and trade links, make relevant blog posts relating to your site and include a link back.
Have you looked around the forum at all? There are tons of threads with suggestions and ideas of how to get backlinks along with traffic. Remember, putting in the time and executing is going to be main components of your success. You can read about a subject as much as you want and people can give you tips but unless you are actually executing on those ideas it's all for nothing. Get a plan together and get started on it. One of the best ways to learn is by trial and error.
You can ask some popular related product review sites to review some of your product. That 'll attract much traffic to your website.
make relevant blog posts relating to your site and include a link back. use Facebook and twitter and Google +1 on your website.
It depends how you want to invest? Do you want to invest more money or more time? If you have the time, search for blogs where you can guest blog and then write the article. This takes time but workds. If you have money, search for linkbuilding companies or high quality marketplaces where you can buy blog articles. Of course there are always different kind of backlinks which you can get, ranging from simple backlinks to complete sub domains. Remember, the sites should in some way or another relate to your product/services/site.
My suggestion is better go for the social bookmarking submission, social networking sites, article submissions, wikis submission etc. You get both traffic as well as back links for your site.
You should add backlinks from sites that rank good in google for the same theme your site is. Buying links from new sites without pr is as well cheaper than with pr as long as you know the owner will do backlinks, for this you can check other sites of the owner to see if he add backlinks or not.