I've setup wired networks before but I have this task I'm trying to accomplish:

Basically, I'm trying to setup wireless connectivity in an office area. It's quite big with 2 2 storey buildings and would require 10-15 routers if I put one every 50 meters. The goal is to have a WLAN with WAN access in every office.

So, I was planning on hard-wiring a router, say ROUTER0 to the WAN modem then put another router (ROUTER1) in repeater mode 50 meters away until ROUTERn. I will then have 1 modem that connects to WAN, 1 router that connects to the WAN modem and repeaters. However, I'm a little confused. The question is, can a repeater be connected to another repeater? For example, ROUTER1 is a repeater; can ROUTER2 connect to ROUTER1 then ROUTER3 connects to ROUTER2 and so on until there's wireless everywhere?

I've been reading around and I've noticed many articles suggesting Access Points over Repeaters. But, I don't fully understand this. I'd appreciate some clarifications.

So, how would I go about setting up this wireless network?

start with a wireless survey, determine the area of coverage for each AP, location for each AP to get the coverage you need and add up the number of AP's you''ll need to deploy the plan.

so first, get a floor layout diagram
second estmate the coverage for 1 AP say 20m.
get out your compass and start drawing 20m circles
on the floor plan to obtain maximum coverage.
get some test AP's, configured, and start walking around
with a wifi laptop, running something like netstumbler.

p.s. this plan leaves out user population density, which will need to be accounted for,

_________________
"If you're good at anticipating the human mind. It leaves nothing to chance."
-Jigsaw

First thing, You don't want to use routers. APs connected back to a (or multiple) switches would be what you would want to do. First thing, follow what Ristau5741 said. All good sound advice. Second, you can daisy-chain wireless repeaters together but I believe there is a limit on the number of repeaters that can be used in a chain. That is not to mention that a wireless repeater has to overlap an existing coverage area by 50% unlike 15-20% if it was 2 APs side by side. Then there is also the issue that your throughput is cut in half by using a repeater instead of another AP. I know that I have mentioned quite a few negatives to using wireless repeaters, but they are good for what they are designed to do which is get wireless to a location that you can't run a cable. If you can run a newwork line, put an AP in. For example if you were to use Cisco equipment, you need to use an autonomous AP anyways so if you can get a network cable to that location then you can use the AP as an AP and not a repeater. Also when you do deploy, make sure that you are using non overlapping channels on neighboring APs. Just my .02.

I'd recommend lightweight APs with a controller. Makes management and deployment a heck of a lot easier.

Hire a professional. You sound like you have no clue at all what's going on in your environment.