It ought to be perfectly simple, but reality and Microsoft have a way of intruding...
If you can make the connection through the router work but it's slow, you may have a problem with the TCP/IP configuration. Here's how it works, approximately. I dunno how much you know already, so I hope I don't insult your intelligence or zoom way over your head here...
You should have two little boxes, one of them being your router, the other being a device your ISP gave you that makes the connection to the Internet. There's a network port on the router that plugs into the dingus your ISP gave you, and that dingus (actually it's called a CSU/DSU, another damn acronym: channel service unit/data service unit) connects to a wall jack that leads out to your ISP's premises. And of course your computers connect to the router.
The CSU/DSU will have an IP address assigned by your ISP, and the information package they gave you should list it somewhere. It should also list a couple of what are called DNS (domain name service) addresses. That's the service that converts between names people understand, like www.canadiancontent.net, and the IP addresses your computers understand. Your router needs to know all three addresses. The router should be accessible via any web browser, and the documentation that came with it should explain the procedure. If that's not the case, then your original supposition is correct: the router's a piece of crap, and you need to get a real one made by D-Link or Linksys.
The router will have a built-in IP address already, most likely 192.168.1.1. That's all your PCs have to know; that's what you give them as the default gateway address in the TCP/IP configuration. Set the rest of the TCP/IP configuration on your computers to the automatic options, e.g. "obtain an IP address automatically" and "obtain DNS server addresses automatically." With XP in the classic view, those are at Start-Settings-Network connections-<pick your connection> -Properties-Internet Protocol-Properties.
And you have to configure the router, which should be explained in its documentation. You have to tell it three things:
1. the IP address of the CSU/DSU, which will be the default gateway for the router.
2. the IP addresses of your ISP's DSN servers.
3. enable DHCP and set a range of addresses for it.
DHCP is dynamic host control protocol. The IP addresses that start with 192.168.1 are reserved for private networks with a router between them and the internet. You can use any of them for your home computers except the first one, 192.168.1.1, which is the internal address assigned to the router. If you enable DHCP on your router and give it a range of IP addresses between 192.168.1.2 and 192.168.1.254, and have your PCs set to automatic as described above, then your PCs will query the router (via their default gateway address) for TCP/IP configuration information, and the router will respond with an IP address they can use in the range you defined, and the DNS server addresses, and some other stuff. You don't need the IP addresses your ISP assigned you, only the CSU/DSU needs a unique address.
I hope that helps a bit. If your router or your ISP won't do DHCP, for instance, this will all have to be done differently. I've also assumed you have real high speed Internet service on a T1 line, not a cable modem. If you don't know what that means, don't worry about it, but the practical implications are that with the T1 service you have a dedicated connection to your ISP, with cable modem service you share the connection with everybody in your neighbourhood your ISP also serves, which may be a source of bogging down.
I've had my wireless router etc. for months but haven't installed it yet because I don't want to have a pissy fit and throw the whole computer off the 15th floor balcony. I'll watch for words of wisdom to you and then maybe I'll get mine up and running too. 
