I'm sure there's some guys here that can give you some better advice than me, but I'd say that you should start with the basics.
Get some social bookmarks pointing to your site. Unless you have a lot of accounts on many bookmarking sites, the best way to do that is buy it from a service. Either go to fiver and buy a $5 bookmarking package, or go to the bst forum here and find a service provider that sells bookmarks.
Then get some links from facebook. Post a link to your site with some kind of non spammy comment on as many walls as you can for profiles and fan pages. Same thing as above, if you don't have a lot of your own pages then just go to fiver or the bhw bst forum.
Make a video about your site and post it on youtube. The best way to do it is make a video that would actually be appropriate embed on a page of your site. (that makes it look less spammy) on youtube. Make an account for your site if you don't already have one. Include a link to your site in the description on youtube. Make posts on other videos suggesting people check your videos as well. There's different ways of doing that and you have to be carefull cause it's really easy to start getting flagged as spam. Just search bhw for threads about how to post comments on youtube. You can also go to fiver or bhw bst threads looking for services to get more views to your youtube video.
Once you've got all that in place it's time to start blog commenting. First make a few free blogs at places like blogger.com and wordpress.com with just a couple simple posts talking about your niche and include a backlink to your main site in the body of the post. Those blogs get indexed fast and so it'll give your site a few legitimate backlinks from some blogs. Won't be real powerful links since there's no pr on those new blogs you make, but it's still a good idea. Then start searching for blogs related to your niche and leave comments on any blog posts you find. Use the keywords you want to target as your username and your site as the url, if you can include an anchored link in the actual comment as well.
You might as well also make comments on many of those blogs pointing to the free blogs you set up as well. That will help build up the value of your backlinks on those posts as well as be a buffer for your real site in case you over do the blog commenting.
Depending on your competition and how well they've done seo for their own sites, just what I mentioned above might be enough to get you're site in the first few pages on google. If your lucky maybe even on the first page.
If the competition is a bit stronger then once you've got those social bookmarks, links on facebook, video on youtube, and found some good blogs relevant to your niche with some good comments linking to your site, it's time to kick up your backlinking campaign.
If you don't have scrapebox yourself, or aren't real comfortable using it. Just go find a service offering blog commenting and buy a package from that service provider.
Then if you want you could also add forum backlinks as well. Just find a service offering xrummer blasts and buy a backlinking package from them as well.
Anyway that's just some basic suggestions to get you started, maybe someone else can give you some even better advice.
edit - Oh yeah I left out articles. Write a few articles and post to article directories with links to your site. You can get that done from service providers as well if you don't want to write the articles yourself.
Hope that helps
