Starting out in networking and security

[digital_nite]

Hello to all,
I've wanted to learn networking and security for a while and after speaking with several people I realized that building my own network is the best way to go. I'm pursuing computer security as a hobby and a future career and I'm keeping things on the legal side. So with that stated I was wondering how you all think I should walk down this path.

What ebooks or printed books should I consider reading?
Should I buy 1 or maybe 2 computers to go along side my laptop?
What type of specs should they have (processor, memory, hd space). I'm on a budget
and am simply looking to learn networking and security.
Should I install ubuntu on all my machines or is there another distro of linux that's free,
easy to install, and security centered?
One last question, (and it's a newbie question) why would one want to learn networking
and security on a windows machine. I know there's money to be made on
installing and managing windows networks, but can't a person connect to
windows machine from linux and practice hacking or other securtiy related
activities including simply transfering files?

Thanks for reading. I look forward to hearing what you all have to say?,
digital_nite

[registered2-5-2011]

you should read the .pdf 'Stealing the Network: How to Own the Box' (fairly available for free on the web) and then research on all the stuff you don't understand(VPN, DNS, TCP, TLS, SSL, ) and learn some stuff. security will come naturally, set up a LAN and a couple of linux boxes and play. But don't 'tard-out' on someone elses net and look like a fool going to jail