Do Not "Switch To Linux"
Using Linux for your first time can be very exciting. You suddenly gain access to a wealth of customization options, all the free and open-source software you could ever want or need, and access to a strong community of (sometimes overly-)enthusiastic Linux users. But before you dive headfirst into this new world, there's an important consideration I'd like to advise you on. It boils down to this: don't "switch to Linux" on your one and only computer. Don't dual-boot it and don't bother with getting a second hard drive. In essence, do not touch your current working computer, no matter what operating system it's running. Leave it fully operational and invest in a cheap second computer instead. You can thank me later!