I write in further support of Perlfect Search,
It will let you create a list of excluded folders/files, that won't get indexed,
and just because it has complex features that you don't need (at the moment),
doesn't mean you have to use them.

I use Perlfect on one of my sites, and it's very good.
The only minus point, for me, is that is doesn't support live searches, so it's necessary to create a cron job to regularly re-index the site.