[CentOS] virtual host on latest centos 4.4

Good morning All,

I have a slight issue with apache virtual hosts not working on my newly
installed CentOS (4.4).

I am very new to Linux, however I have experience with apache etc on
'w1nd0ws'. I've been round and round in the apache conf file and to no
avail. 

Basically if I setup a virtual host the default then looks at it. Also,
if I setup multiple virtual hosts they all look at the first virtual
host.

I'm running the machine inside my local network as a staging server for
web design. I then set my HOSTS file on my PC to the ip of the server
and then the www.domain.co.uk:

Eg:
192.168.1.250	www.testsiteonvirtualhost.co.uk

This is what I do on my other apache test server (not CentOS). I assume
this should work??

Is there anything other than virtual hosts that would need setting up?? 

Thanks in advance.

Mark.