Hi ranga,
First of all welcome to the Beat the Gmat community, this is one of THE best site which u can find to help u in all times
To begin with take a diagnostics test so that u knw where u stand at present, there are so many free cat tests available(u can find links to some of them on the homepage of this community)
Once u take the diagnostics, start of with ur prep either by enrolling into some course and wrking on ur weak areas, also these courses come with loads of practise probs and cat's which u can use or u can also studying on ur own if u want to.
There are ppl here in the community who are alwz there to help us in most of the ways.
Take start, kick off ur prep with a diag test.
some ppl take the GmatPrep test1 as a diagnostic which i never feel is sensible...!! take gmat prep only when u feel you are ready for the test, cause these cat scores are like the real gmat and scores are almost representative of the real gmat.
take diag either from kaplan, manhattan, vertias, princeton, knewton or some other authentic source.
All the best
PS: Kindly ignore typo and grammatical errs.