Hey Murph,
Youve made a great choice going with the D90 (most of the guys who replied to this thread helped me decide on buying one a while ago) As far as lenses go I think you have a good range for portrait, wide angle and zoom......not sure about the 18-55mm I think thats a "kit lense"? Ive only just bought a Tamron 90mm Macro and I have the 18-105mm, yet to get extra lighting and a tripod..... Get a tripod and you should be well on your way to taking some great photos.....