Information is the name of the game. People go onto the web looking for information on a product, an author, a service, a problem, a hobby, a job. Your business probably isn't to provide information; but if you want people to come to your web site, you need to provide something they want to come for. People don't come just to buy; they come to shop, which starts with finding information. That's why Amazon, Ebay, and Buy.com, all extremely commercial retail sites, contain so much information.
But if the user can't find it, they give up on your site and go elsewhere. The primary ways to help the user find information are good information architecture and site navigation, and making sure that external search engines (particlularly Google) index your site well.
But for some kinds of sites, a local search function is useful as well. The easiest way to do that is to use a Google feature that allows you to put a Google-branded search function on your web site which simply restricts a Google search to returning results that are on your web site. They also have fancier commercial options available. This may be the right solution for some sites; in fact it might well be the right solution for the Uncle Hugo's site.
However, having your own search function that you control, which you can be sure indexes your entire site, and which updates when you want it to, will get the results you want to your users more reliably. The price you pay is an unfamiliar (to your users) search syntax, and quite possibly less powerful search capabilities. The search function on unclehugo.com is implemented using the htDig package (free software), which does have both of those problems.