fafi choy,
IMO, since newbie ka pa lang nman, maganda siguro if you go with the kit.
the D90, afaik, comes with the 18-105mm if am not mistaken. ok na sya for an all around walkaround lens [pero the best for me is the 18-200mm, pricey nga lang], combo na sya ng semi wide to zoom. then as you go along and hone or define your shooting style, that'll be the time when you can decide what lens to get that suits you. iba iba kase ang need depende sa kung anong klaseng subject and style of photos you want to take.
just my two cents worth.
cheers!
phantom