Working on securing my home network, messenger programs, email accounts, internet usage etc.

Looking for advice on good programs/hardware and on how to setup.

I want to setup a wireless network of 2 desktop IBMS, a desktop Mac, and a notebook (IBM). If I setup the router and direct cable connection (cox) through the macintosh then I avoid the internet security issues associated with IE and XP, what else can I do for this computer to agressively prevent key loggers, etc. Yes there is an active threat. I am not as familiar with Macintosh as I should be, what is the best firewall I can get for the Mac?

S***estions for securing the instant messaging and email programs through the mac?

I have pretty much given up on most email programs, my hotmail, yahoo and gmail accounts are easily hacked. Started going towards encrypted email solutions. Is there a paticularly good encrypted email program out there? free or cost, I am open to what works and works good.

Once I network my other two desktops and the laptop to the wireless network what can I do to secure them?

S***ested firewall software for the IBM computers as far as the hardest to hack?

A better messenger program or ways to secure any of my current programs?

Also any advice on what is going to be the most secure browser?

Any advice appreciated.