firewall?
 

does redhat linux have a firewall and if it does, will it stop other computers on a network from talking to it? e.g winxp and rh8

yes - you can use a tool called "lokkit".

I should also point out that it doesn't do the firewalling itself. It creates rules in iptables to do that. You can view any current rules with:
iptables -L

so do you think that the firewall on my linux comp could be stopping windows from accessing samba???
or should i not worry about that?

It is perfectly possible - you need to let the windows machine access ports 136, 137 & 138 on the linux box. Like I said- you can view your rules using:
iptables -L

You can remove all of them (flush them) with:
iptables -F

This is only temporary and the saved rules can be reloaded using:
service iptables restart

Once you have rules set up that you are comfortable with - you can save them using:
service iptables save

AFAIR samba uses ports 137,138,139 rather than 136, 137 & 138.

your right - sorry, my mistake :rolleyes: