If all you are going to do is internet and Office type work then almost ANY laptop you buy nowadays will be good enough for that, so dont get too bogged down in techncial specs.
Things to consider are:
Get a good reliable make, not a no-name cheapo from a supermarket or PC World.
If you are going to carry it round a lot consider the weight, which will be important. Go for a 15" or so screen.
If it is going to be in one place most of the time consider a 17" screeen, more desktop.
If you are going to be on the road a lot then battery life is important.
Dont buy one with Vista Home Basic, go for Vista Home Premium (more goodies). Note that Vista Business has many "home" type applications missing so dont go for that if you may use them.
The things above are probably more important than if it has a slightly faster CPU than another laptop.