some use tutorial of iptables

http://iptables-tutorial.frozentux.net/iptables-tutorial.html
http://www.netfilter.org/documentation/
http://www.faqs.org/docs/iptables/index.html

use ntlmaps for ISA proxy

if you have any problem with ISA proxy and linux, try ntlmaps

Best FS on linux

It uses the maximum capacity of your server hard disk(s)
It is the quickest FS to create, mount and unmount
It is the quickest FS for operations on large files (>500MB)
This FS gets a good second place for operations on a large number of small to moderate-size files and directories
It constitutes a good CPU vs time compromise for large directory listing or file search
It is not the least CPU demanding FS but its use of system ressources is quite acceptable for older generation hardware