Ad Sense question

I want to advertise in adwords under a bunch of search terms. Is there an easy way to do this while also customizing my ads. For example, if someone does a search for "books", I would want to say "buy books here" and if they search for Magazines, I want it to say "buy magazines here"

Nothing. But you can manually create different ads. for different keywords;

You can use the google's dynamic keyword insertion tool

Buy {KeyWord:Books} Here

and you can add several keywords like
Magazines
Cheap books
Cheap magazines in your ad group.

If anyone searches for Cheap books., your ad title will be like:
Buy Cheap Books here

if no query of the user matches your list of keywords., then the default ads will show.

"Buy Books here"

Using KeyWord <<<--- will make your title as Cheap Books
Using keyword <<<--- Will make your title as cheap books
Using Keyword <<<---- will make your title as Cheap books

Its very effective tool