First Time Installing Linux
Before you begin anything it is always good to know what you're getting into and have a plan, the same is true of installing Linux. Hopefully I don't make it sound to difficult and scare anyone away, but there are a few things you need to think about before you start.
After you have decided which brand of Linux to install you need to decided where to put it. On an empty hard drive is the easiest, even a second hard drive will work. I'm betting that most first timers will be setting up a dual boot with Windows or another OS already installed. If your system has a huge multi gigabyte drive that you are only using a fraction of then it doesn't make sense to buy another hard drive when there is already all that empty space. If the drive is divided into two or more partitions and you can empty one then you're in business. If the drive contains only one partition don't give up yet, the newest version of most of the more popular Linux distros come with tools that are capable of repartitioning a hard drive that contains data without destroying the contents. There is also commercial software such as Partition Magic that can do this. You will need to read up on the tools that came with your Linux version because they are all different. And you would be wise to backup any important data.
How much space do you need for Linux? Well I once installed Red Hat 6.1 on a 450MB drive, but I had to leave alot of stuff out and there was almost no free space left. I then whittled out some more unneeded stuff and gained some more free space, but not a lot. If you want plenty of software to play with and room to install more later you will need at least 2GB, more would be better. My current Linux installation is in 6GB, about half of that is free space.
You should gather as much information about your computers hardware components as you can, things like model, and chip set of your sound card and video card, info on your SCSI devices, CD drive, DVD drive, modem or network adapter, your monitor, and your printer, and any other components you may have. This info may come in handy later if the setup program asks for it or fails to properly identify some component.
The setup is usually run from a bootable CD, most newer computers support booting from CD but you may need to enable it in the BIOS. An easy way to find out if your computer will boot from CD is to put your Linux installation CD in the drive and reboot. If the Linux installation program starts when the computer restarts then you're all set, if not you need to enter the BIOS setup to enable booting from CD. The BIOS setup is entered by pressing a key or combination of keys at the right time wile the computer is booting. On my computer I see the message "press del to enter setup", the Dell computer I use at work says "press <ctrl><alt><enter> for system setup", yours may be different. Look for an entry in setup called boot sequence, or boot devices, or something similar and change it to check for bootable CD before booting from the hard drive. Some computers just will not boot from a CD, if that is your case then you will need a floppy boot disk. If you bought a box set there should be a boot disk included, if not the necessary files for the boot disk are probably on your installation CD, or they can likely be downloaded from the web site of the Linux distribution you are using. The manual or readme files on the CD will help you find them.
When you're finally ready to install it shouldn't be to tuff, read the manuals first, they can explain the steps of the installation better than I could. If you didn't buy a box set with the manuals included check your CD, all the info you need may be there, also check the web site of your chosen Linux distribution for downloadable documentation.
Maybe I should say somthing about hard disk partitioning here because it seems to be a scource of much confusion for new Linux users. Linux installations are often spred over several partitions in order to separate and organize diffrent parts or the system. The question of how many partitions and what size they should be has as many diffrent answers as there are pepole to ask. My advice, take the easy route, make a 250MB swap partition and use the rest of your space as the / (root) partition. This will work fine, there is no need to waste time worrying about paritiions. Later when you have more experience with linux you can work out a custom partitioning scheme to fit your needs.