DNS,Proxy Server and etc

first of all...i really dont know anything about this stuff so i really going to need your help on this things...

situation:
they'd register (for example: whoyouare.net) in yahoo.com for DNS registration...what they want to do is setup a server so when a user wants to view (whoyouare.net), yahoo will redirect it to our server (pls correct my understanding if im wrong) where the static Ip (given by our ISP) is registered in yahoo.com (whoareyou.net = 128.128.128.99).

also, we have 3 different Internet connection (all broadband).

What they want to accomplish:

1) they want all 3 internet connections to be used all at the same time, which from my understanding, when 1 or 2 of the internet connection goes down, the active connection will still provide internet connection to other client computers...how will i do it??? pls provide different solutions...also is squid required???

2) is it possible to access a specific computer in the internet??? what i mean is this...they want to access pc01 in whoyouare.net (pc01.whoyouare.net) how should i do it? should i configure it on the Yahoo.com? our Server? should it be done by configuring BIND on our server??? pls advice...

up........

accessing pc01 on your network can be accomplished in several ways depending on the structure of your network. You could have your router/gateway forward all inbound traffic on port 80 to that machine, if the machine is the ONLY webserver for that domain you could simply point your DNS to that machine's IP address.

As for aggregating 3 connections for backup purposes, the easiest way is to run your own DNS server and put in the hosts file the alternate IP addresses for the machine. The only drawback to this setup is that it will require your machine to have 3 separate IP addresses. One from each hosting provider.

There are literally hundreds of ways you could accomplish this, but the majority of them are designed around you having certain hardware configurations. Without knowing the nature of your connections, your hardware, your network, it's hard to make a suggestion.

we have 3 broadband connections with all with routers each...how am i going to start with this? i really dont know where to start...we also have a switch, an airport, linksys router...can you pls suggest what you can..

do you also suggest to have our OWN DNS server?

3 connections with routers? My suggestion would be to pay an IT person to come do it for you. Once it's set up you should have no real maintenance to speak of. I could be more specific, but realistically trying to tell you how to do this over the forums could end you up with 0 working internet connections if you get stuck somewhere along the way.