Search Engine Optimization Question

Depends....If the keyphrase is going to "compete" with keyphrases that you use on your homepage, I wouldn't link to the individual pages. If you are trying to optimize for an individual item, I would link to the specific page.

Does that make sense?

I would say individual product page.

If you are talking about a product than you should link to that page regardless of whether it competes with the homepage or not. All you are doing is building link popularity.

If your homepage already has links going to it then you should boost your other pages. If your homepage doesn't already have enough links going to it then link the more general keywords back to the homepage and link the product specific keywords to the product page.

Think of it as spreading the 'link juice'.

Is there a book or website somewhere that details how to SEO, what the search engines rank on, etc.? I think I've got it down but I'm figuring there's probably something I'm missing.