Search engines - what is the point?

[AllButOne]

There is one thing I do not understand about search engines.

If you type, for example, "Japan tourism business" into Google you get 
26,000,000 replies.

Now, how can any company involved in business tourism who is not in the 
top 100, let along the top 500 compete.  No one is going to scroll 
through more than a dozen or so pages at most.  Certainly not more than 
50 pages, and that would be unusual.

So, my point is: if one was creating a website for a new business, would 
that person not have a tremendous disadvantage since noone would ever 
see the company's page since it would be so far down the ratings.

I know that one could buy Google adspace and be one of the sponsored 
links, but if you didn't do this, how would anyone see you.

And can anyone suggest a guide to understanding how search engines work 
for the novice?

Thanks, very much appreciated.