I have a desktop computer that is not hooked up to the internet, nor has been. There is a WiFi hot spot down the street; since it is free I would like to be able to connect to it. What do I need to buy and do to get up and connected to it?
You need two things to connect to that local hotspot - one you can probably buy at any computer store, but the other might be harder to come by.
Let me explain...
First the easy part: you need a wireless network adapter. WiFi (802.11) adapters are pretty much standard equipment in laptops these days, but not in desktops. Since desktops aren't (typically) mobile, they assume you'll used a wired connection and thus include a wired ethernet adapter instead.
You can add a wireless adapter to your system in several ways (links take you to example components):
An add-in card - unlike laptops, desktops are designed with several slots for expansion cards, and wireless adapters are, indeed, available as expansion cards. In general, for a permanent installation, this is probably my first choice.
A USB plug-in - wireless adapters are now also available as devices you just plug into any available USB port on your system. Many are small, convenient, and quite inexpensive.
A wireless bridge - these devices plug into your existing ethernet connection and, effectively, transform it into a wireless connection. This is probably my least favorite approach, only because it's fairly uncommon, and I've had no direct experience with it.
"My strongest recommendation is that before you embark on trying to get your computer connected wirelessly is to make sure it'll work first."As I said, I've linked to examples of the components that I'm talking about so you can get an idea, but there are literally thousands of alternatives. I happen to be a fan of LinkSys equipment, but again, there are many reputable manufacturers out there as well.
The bottom line is that getting your PC wireless enabled isn't that difficult.
This phrase in the question concerns me: "There is a WiFi hot spot down the street...".
How far is "down the street"?
WiFi hotspots are typically fairly small. The semi-official range of WiFi is about 300 feet, but even that can be seriously impacted by the characteristics of whatever else might happen to be between your computer and the hotspot.
My strongest recommendation is that before you embark on trying to get your computer connected wirelessly is to make sure it'll work first. Borrow a WiFi enabled laptop, or borrow a friend with a WiFi enabled laptop, and see if they can connect. There's a good chance that they may not even be able to see a signal, if "down the street" is anything more than a couple of houses over. While you're at it, you might also use that as an opportunity to see if different locations in your home will get a signal, or get a stronger signal than others, since the laptop will be much easier to carry around for that test than your desktop will be.
And after all that, if it does work, I suppose you should also have permission of the hotspot owner, since they typically provide hotspots as part of their business, as a perk for their customers - which you presumably are not. But ultimately that's a different topic I won't get into further.
And a final caveat: if you're using a public WiFi hotspot that is unsecured, your internet traffic may be subject to sniffing. Make sure you're taking the appropriate steps to keep yourself safe and secure.