I replaced my Wireless G with a Linksys Wireless N (WRT150) router in
order to try to get better range but have noticed no difference to my
laptop in the 'dead room'. The laptop uses a wireless G notebook
adapter. Before I waste any more $... will buying a wireless N
notebook adapter have any beneficial impact on my range problem?

Would an access point help me? If so, how? And is an AP complicated
to set up?

Thanks!