I've not had a great deal of luck so far connecting to the internet in Mandrake Linux. I have indeed connected to the internet in a fashion and managed to get programs such as aMSN, Yahoo Messenger and Zinc online and working. However when browsing the internet i usually got the following error on 80% of the pages i visited:

An error occurred while loading www.yahoo.com

Timeout on server
Connection was to yahoo.com at port 80

So the first thing i'd like to do is go right back to the beginning and make sure i configured my connection correctly. First of all i have to ask, am i supposed to configure my internet to ADSL, LAN, or MODEM? I know i can't configure it soley to LAN because there is no option for me to enter my Username and Password to get online with my account.

In windows all i need to get online is this Username and Password. But Mandrake Linux is being quite difficult. I am connecting to the internet via my nVidia integrated Ethernet port (which seems to be picked up in Linux without any problems) and a D-Link DSL-504T modem/router/firewall which sends 512k to me and 512k to another computer.

I'm going to disable ipv6 in firefox as follows:

type in the address "about:config"
type "ipv6" in the filter
change the line:
"network.dns.disableIPv6" to TRUE
and restart browser.

I'm also awaiting an email from my ISP which will inform me of my exact DNS in order to add that information to the relevent Linux setting.

Question: How exactly do i set up the internet PROPERLY in order to get unrestricted access to the internet on boot up. E.g. The ability to browse 100% of websites (or at least 99%) without getting the above error message.

Any advice much appreciated.

You didn't tell about the internet connection type , i.e., whether it is DSL, or Cable, and whether your network uses privet IPs, such as 192.168.x.x.
But I guess you are using DSL because the modem/router says DSL. Also the other computer is hooked up to the modem.
So I am guessing again your computers are using privet IPs , and it is assigned automatically by DHCP server function of your modem.
So, all you have to do on your computer is configuring your network as LAN and setup a proper gateway IP and DNS. Gateway IP would be 192.168.x.1 usually although it depends on the modem setup. DNS could be any working DNS in the world. It is necessarily to be your ISP's.

The user name and password for internet connection have to be saved in your modem. There is a way to save those. Try this.
Open up your web browser and type 'http://192.168.0.1' in the URL window. Here I am guessing again that the modem uses 192.168.0.x network for privet network. If you see any configuration menu on the browser, your gateway IP is 192.168.0.1 and you are almost there to finish the work. If you don't see the configuration menu, well, then you have to take a look at your modem manual and find out what IP you have to use to login to your modem. Manual would say how to setup your ID and password for internet connection. Once you did you don't need to do it again unless you reset the modem to factory default.

I hope it could give some idea.