It's vary depend upon keyword competitors having high competitors means take more time, do more link building otherwise easily bring on 1st page of google search results.
It totally depends on what you’re trying to achieve. The more you want to achieve (in terms of keyword targets, rankings and visitor numbers), the more back links you’ll need.
There are lot of ways to get quality back links,like forum post,blog commenting,guest post,social media etc etc Use all link building techniques to build backlinks.Try to get backlinks from do follow,high PR and relevant websites..
for better ranking you can increase backlinks through
1. Blog Commenting
2. RSS Directories
3. Social Bookmarking
4. Video Sites
5. Guest Posting
6. Internal Links
you can also hire experts from SEOclerks.
If you get a backlink from Trusted and High PR site then your site will surely get a good rank and reputation.So, you can create as many backlink as you want there is no fixed limit. Large amount of spammy links doesn't give you a good rank.
methods for getting backlink for a site are:
1) there are various online directories avaailbale where you can submit your website in the proper category (these directories aloow 3 types of links : i) free ii) reciprocal iii) paid inclusion.
I suggest you to go for free inclusion whereever possible
Paid inclusion should be done only if the directory has good page rank otherwise its waste of mony
Reciprocal links are of no use as google doesnt give weightage to them.
2) also post the details of your website in classifieds which is a better and quick ways to generate backlinks.
3) Article marketing is also a good way to generate quality backlinks.
4) Use social networking websites and create your profile and participate in discussions and q&a there, it will also help you increase backlinks.
you can also hire experts from SEOclerks.