Landing page for search engine visitors

I’m quite new to WordPress, and I’ve just got a stats plugin called New Stats Press that’s giving me detailed information on where my visitors are coming from. One of the things it shows me is the search terms visitors have used and which page they viewed.

Sometimes they are sent to a specific post (which is good), other times they’re sent to a page or category listing that contains the relevant post (which is less useful because the post that’s relevant to their search can be at the bottom of the page).

Is there something I can be doing when I create my posts to help the search engine spiders index them better, so people arrive at the right place for the information they searched for?

(I realise this may be a very general question about SEO, which I don’t understand at all, but if there are any useful sites you could point me to for more information, that would be helpful.)