How many articles for one long-tail keyword?

Hi all,

I'm just starting out creating my first niche website and have done a lot of keyword research in finding one that I think has low competition etc. but how many articles do I write targeted at this one long-tail keyword?

I have written an 800 word article based on it that sits on the front page but then obviously I need to add more content but don't know if focusing future posts on the same long-tail keyword would work against me.
Do I need a new long-tail keyword for each of these new posts?
And will the one page on the home page be enough to rank for my main choice longtail keyword?

Thanks in advance,
Sam

 

All Keyword was not required articles some keyword optimize by Image alt and H1 , H1 tag.

 

Do not use same keyword for more than one article, try to keep up a variation on keywords. example:how to transfer domain in GoDaddy and you also can write it " transferring domain to GoDaddy". not the same keywords but same meaning with different words.

 

Ah great thankyou for the advice memithun, much appreciated.