I just took the plunge myself so I may be able to shed some light based on my experience over the last couple of weeks.
Here is what I set out to do and how I went about it.
I wanted to learn about Linux.
I wanted to have a dual-boot system on my Desktop and Linux only on my Laptop.
I wanted to network the two regardless of what OS was loaded on the Desktop.
I did not want the hassle of repartitioning my hard drive.
I wanted to gradually shift to Linux as my primary OS as became more capable. This meant email, encryption, office apps, etc.
I didn't want to spend any money.
What I did was this.
I downloaded Mandrake Linux from their website for free. Burned it to CD-rom as an image and installed it on my laptop (Pentium II 450Mhz).
The chose to completely repartition the hard drive and remove Windows. The install was very straight forward and took about 20 mins.
I chose not to log in automatically so I would have the option to choose between KDE and Gnome as my GUI. I decided to stick with KDE for the most part.
After the install was complete the wizard walks you through setting up Kmail which I find to be excellent email client. I was able to connect to the internet right away with no trouble at all.
The first thing I did when Linux was up and running was to install OpenOffice (
www.openoffice.org) the windows version of which I have used for quite a while. OpenOffice is superior to MSOffice in my opinion and will work with MSOffice files with no problem, and it is free.
Next came GnuPG which is Public Key Encryption for Linux. It typically runs from the command line but there is a great graphic interface available called KGPG which I found online as well. The guy who wrote it was great about helping me out despite the fact that my questions were pretty simple. In short order I had GnuPG up and running and had used KGPG to import my keys. Everything integrates seemlessly with Kmail as well. And btw...all free.
When it came time to install Linux on the desktop I went to a local computer show and bought a 6Gbyte Hard Drive for $20. This is the only money I spent on the whole process. I installed the new drive at the end of the line and set the drives to cable select so the new drive was master. I popped the same CD I used for the laptop install into the CD-rom drive and installed Mandrake to the new drive. Again, everything went like clockwork, and no one lashed me to a yardarm and flogged me for piracy. When you do your install this way you don't have to touch your Windows drive and Linux will give you the choice of booting Linus or Windows at start-up. The Linux OS sees both drives with no problem but not the other way around so I keep all my files on the Windows drive.
Next came the part I feared most...setting up the network. No problem. I installed LinNeighborhood (very well documented) and I can access file from the Laptop easily whether the Desktop is in Windows or Linux.
Make sure you download RPM files designed for Mandrake and look for pre-compiled versions (cookers) rather than source code if you want to install with a click of the mouse.
Don't be afraid to experiment.
Ingnore anyone who responds to a question with RTFM. Chances are they either can't find their butt with both hands or the manual is a piece of crap (often the case) and they wrote it.
Good Luck and have fun.