A good many months ago someone posted a good how to on using a second wireless router to extend the range of the main one (with all the best settings to use to get it to work). I have been searching through lots of posts and cant find it so if anyone can point me in the direction of that would be great.

dont know where the original post is, but:

on the second router, ensure its management address is different from the first **
and switch off its dhcp service.
select the wifi to have the same ssid, but on a different channel.
wire the two together with ethernet.

** best to allocate one in the same subnet, so if first is on 192.168.1.254, use 192.168.1.250

TP-Link TL-WR841N 300Mbps Wireless N Cable Router

I used a couple of these around the house recently one in the workshop of course. I just put a LAN cable between the Network router and the slave routers configured the second router to Firewall off and WAP security definitely on. Configure the router before you plug in the LAN link. I am not a network type person but it worked for me. No doubt there will be a guru that comes back to me. My understanding is you can create problems for yourself if you have two or more extra firewalls. There is a firewall in the WAN router and there will be one in each PC/Laptop connected to the network if you add one or two more then expect trouble IMO.