DNS:

[#1]

Is there a way to set your own DNS servers in the router, the one that plusnet supplies?.

[#2]

Yes,  but as they supply a few - which one?

[#3]

My preference is to set it on each PC so that the routers DNS is totally bypassed.

[#4]

You could do it this way, but that means doing it on every computer, doing it from the router doesn't mean you have to do that.

[#5]

Quote from: dvorak

Yes,  but as they supply a few - which one?

Technicolor tg582n.

[#6]

Possible, but not intuitive.
You'd need to run a few commands using telnet and the CLI interface. From a command prompt type the following and press enter:

telnet 192.168.1.254

You'll be prompted for the admin username and password. Unless you've changed this, the username will be 'admin' (minus the quotes) and the password will be the serial number on the base of the router (it's case sensitive so any letters need to be typed in upper case).
Once you're logged in run the following commands in order, pressing enter at the end of each. You should replace the x's with the DNS server addresses you're wanting to use. The first is the primary server address, the latter the secondary.

:dns server route add dns=xxx.xxx.xxx.xxx metric=1 intf=Internet

:dns server route add dns=xxx.xxx.xxx.xxx metric=2 intf=Internet

:saveall

quit

That /should/ do the trick.

[#7]

Thanks, i will try it, how would i go back to the original dns servers if i wanted to?.

[#8]

Delete the unwanted DNS IPs using the delete command mentioned in the How to change the default DNS servers in a Thomson Speedtouch router library article.
Don't forget to saveall afterwards.

[#9]

Quote from: tomxlisa

...but that means doing it on every computer,

DNS server address is usually an option in a router's DHCP server set up. 
So you could set the DNS server addresses you want to use in the routers DHCP server options and you don't have to set it on every PC. 
A little more detail.
Routers typically make little or no use of DNS themselves.  Some routers provide a DNS cache, which should provide a quicker response (in theory) to the PCs configured to use it.  However, in my experience cheap routers can be so underpowered that cached responses are slower than forwarding.
I should point out that I have little experience with PN provided routers.