as i am a newbie, can you please suggest me some topic where competition is less and to reach higher in search engine positions is easier..its ok if they are comparitively less paying topic
I am going to say this as nicely as possible...What you are asking is the thing that most webmasters on this forum try to protect more than any other SEO tactic. Our niches are our livelihood and if we have one that is good, we will develop it, not give the idea away and let you make all the money.
You wouldn't accept any job just because it's easy and pays good money - or we'd all be drug mules and hookers. You have to love what you do. Now, cellphones pay well and I bet I could get good SERPs but I'd be bored. So I focus on what I like. Now, I reckon you could do well with pet fashion - the kind of crap the likes of Paris Hilton wraps their silly dogs up in. I have no interest but for some people it's intensely interesting. You can't add value unless you think your site is intensely interesting!
who should? the site? is it selling something? or just relying on adsense? Oh, and welcome to the forum!
Create a website for a topic that you really like, for example if you're a big baseball fan, create a website about it, create unique content, sell online tickes, provide information and so on. See sarahk's #3 post! Be Motivated, Build, Promote and Grow. And check this website: http://www.jimboykin.com/building-backlinks-through-content-advice-and-tips/
Get an AdWords account (it'll only cost you $5-10) and do your own keyword research. It's easy, it just takes an investment in time.
I will suggest "Bluetooth" related website ... but it should good & up2date + daily news and chitika can perform well on that site .....