those 2 tutorials explain the general gist of software raid on linux extremely well. i assume you want something which is more step-by-step. if this is the case, it will be very distro-specific. please let us know what distro you are using. having said that, software raid in linux (provided by md) is pretty standard across all linux distros... so you can probably adapt the instructions even if your distro is different.
before continuing further, ill answer your last question. /dev/hdx is generally idicates that the device is IDE/Ultra ATA. /dev/sdx generally indicates a SCSI or Serial ATA device. this is the general rule of thumb for linux 2.6 kernels. for linux 2.4 kernels, Serial ATA devices could be shown as /dev/hdx.
to setup raid1 on your computer, you will need to decide if you want to use hardware RAID (if available - please let us know what hardware u are using, eg. motherboard with on-board raid, or 3ware PCI-X card?) or software RAID provided by Linux.
there are advantages and disadvantages with both options. you will need to decide for yourself - but a lot of information is out there on the web. please let us know what you have decided. don't forget to mention your hardware specs and the distro you're using.
once we have more info, we can continue further...