1) see click here
2) Well I've tried two. Redhat Linux and Mandrake. I would say Mandrake is more better but at the sametime you have to learn Linux so either will do, to learn all about Linux.
3) Linux has good support for all hardware. Drivers are dependant upon the manufaturer of your hardware. Simply go to the website of the hardware component and see if there is one. But i'll doubt you'll need one.
4) In order to install Linux onto the one HDD. You need two partitons. One for Windows and one for Linux.
Two ways: Reformat the drive and create two partitons or buy PM click here and resize the windows partiton to make anoter one.
I prefer the format option.
To see what Linux is all about, to see what you are in for click here you do not have to install. It will run from the CD. So you can have a peek at Linux before deciding to install.
"and any other relavent info that might be useful." - Only download if you have broadband. Best to let it download overnight. I find download managers are better click here