Dual boot Mac and Windows 7 Where to begin

I have an AOA150-1504 currently running XP. I was going to upgrade to Windows 7, but have decided I'd also like to give Mac OS a try to see what it's all about. I have upgraded my system with a 320 GB HD and 1.5 GB Ram. I have few questions about where to begin with this whole dual boot process. I know there are several guides out there, so I'm hoping people can point me in the right direction rather than ask for the wheel to be reinvented in this thread. I have searched, but I'm seeing conflicting information so it would be great if someone could help with AOA specific info.

1. I plan to completely wipe the hard drive including all of the Acer partitions, since I won't need them anymore. I do have the Acer partition disks and XP recovery disks in case something goes wrong so I can get the netbook back to normal. If I wipe the disk clean, should I install Windows 7 or Mac first? Do I need to make separate partitions first?
2. Where and how can I obtain a copy of Mac OS? Do they have a "trial". I've never used a Mac before, so this is just to experiment and see if I like the OS.
3. From what I've read, nothing likes the built in in Atheros wifi card. I have no problem cracking it open, but want to make sure I swap for the right card. Is Dell 1390 mini-pci-e compatible with both Windows 7 and Mac OS? I'[m having trouble finding confirmation of this.
4. I have seen that the card reader is not supported in Mac. Is the expansion slot supported? My cameras use SD cards, so as long as I can use the expansion slot for that I can live without the card reader on the Mac side.
5. I see many tutorials that say to use an 8GB USB thumb drive. Is this just because they assume most don't have an external CD drive? I have an external USB CD drive, so will that work, or is there another reason to create the USB thumb drive?
6. Is there a tutorial or tutorials that can walk me through a dual boot on a brand new HDD?

Thanks in advance.