Is it possible to set up a raid just using software or do you need hardware support to do it?

you need a raid controller to set up RAID, if you are using sata drivers this mean that you already have one, and all you need is to read how to set it up. anyway there are other sollutions, for example make scheduled backups of your staff, as for me it's much better then making mirroring raid for home use, you can use for example well-known progs like true image.